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IMPRESSUM J o u r n a l o f A p p l i e d E n g i n e e r i n g S c i e n c e (J A E S) The journal publishes original and review articles covering the concept of technical science, energy and environment, industrial engineering, quality management and other related sciences. JAES is Open-Access Journal that follows new trends and progress proven practice in listed fields, thus creating a unique forum for interdisciplinary or multidisciplinary dialogue. JAES is part of the electronic journal editing with a transparent editorial and review policy. Provided are: • Online paper submission and tracking of review process with communication between editors, authors and reviewers • CrossRef: assignment of numerical identifiers (DOI) to assure greater visibility and accessibility of journal articles • CrossCheck: control for originality of submitted papers, to prevent plagiarism and duplicate publications • KWASS: automatic extraction of keywords from disciplinary thesaurus • Online-first publishing • Automatic transfer of metadata to SCIndeks that support international protocols for data transfer All published articles are indexed by international abstract base Elsevier Bibliographic Databases through service SCOPUS since 2006 and through service SCImago Journal Rank since 2011. Serbian Ministry of Science admitted the Journal of Applied Engineering Science in a list of reference journals as Leading national journal M51. Same Ministry financially supports journal’s publication. Publisher Institute for Research and Design in Commerce and Industry - IIPP; www.iipp.rs For publisher: Mr Nada Stanojević Copublisher Faculty of Mechanical Engineering – Belgrade University; www.mas.bg.ac.rs For copublisher: Prof. dr Radivoje Mitrović Faculty of Transport and Traffic Engineering – Belgrade University; www.sf.bg.ac.rs For copublisher: Prof. dr Nebojša Bojović Editor in Chief Prof. dr Gradimir Danon Faculty of Forestry, Belgrade; Honorary Editor Prof. dr Jovan Todorović Faculty of Mechanical Engineering – Belgrade;

International Editorial Board Prof. dr Vukan Vučić, University of Pennsylvania, USA; Prof. dr Robert Bjeković, Hochschule Ravensburg-Weingarten, Germany; Prof. dr Jozef Aronov, Research Institute for Certification JSC, Russia; Prof. dr Jezdimir Knežević, MIRCE Akademy, England; Dr Nebojša Kovačević, Geotechnical consulting group, England; Adam Zielinski, Solaris Bus & Coach, Poland; Prof. dr Miloš Knežević, Faculty for Civil Engineering, Montenegro; MSc Siniša Vidović, Energy Testing & Balance Inc, USA; Dr Zdravko Milovanović, Faculty of Mechanical Engineering, Banja Luka.

Editorial Board Prof. dr Miodrag Zec, Faculty of Philosophy, Belgrade; Prof. dr Nenad Đajić, Mining and Geology Faculty, Belgrade; Prof. dr Vlastimir Dedović, Faculty of Transport and Traffic Engeneering, Belgrade; Prof. dr Mirko Vujošević, Faculty of organizational sciences, Belgrade; Prof. dr Vladimir Popović, Faculty of Mechanical Engineering, Belgrade; Prof. dr Vesna Spasojević Brkić, Faculty of Mechanical Engineering, Belgrade; Prof. dr Dragan Aleksendrić, Faculty of Mechanical Engineering, Belgrade; Prof. dr Željko Kamberović, Faculty of Technology and Metallurgy, Belgrade; Prof. dr Mirjana Misita, Faculty of Mechanical Engineering – Belgrade; Prof. dr Dragan Milutinović, Faculty of Mechanical Engineering – Belgrade; Prof. dr. Nenad Zrnić Faculty of Mechanical Engineering – Belgrade;

Publishing Council Prof. dr Radivoje Mitrović, Faculty of Mechanical Engineering, Belgrade;

ISSN 1451-4117 UDC 33

Papers are indexed by SCOPUS

Milutin Ignjatović, Institute for Transport and Traffic CIP, Belgrade; Dragan Belić, Transport Company “Lasta”, Belgrade; Dr Deda Đelović, Port of Bar, Bar; Dr Drago Šerović, Adriatic Shipyard, Bijela; Cvijo Babić, Belgrade Waterworks and Sewerage, Belgrade; Nenad Jankov, Power Plant Kostolac B, Kostolac; Miroslav Vuković, CBRE Serbia, Belgrade; Dušan Đurašević, Euro Sumar, Belgrade. Editorial Office Nada Stanojević, Miloš Vasić, Darko Stanojević, Miloš Dimitrijević, Ivana Spasojević, Milica Mikić, Nemanja Milenković, IIPP, Belgrade; Printed by: Planeta Print, Belgrade Designed and prepress: IIPP Journal of Applied Engineering Science 13(2015)4

CONTENTS

Vlastimir Radonjanin, Mirjana Male ev, Ivan Luki , Slobodan upi , Suzana Vukoslav evi THE ASSESSMENT AND REPAIR OF THE PRECAST RC STRUCTURE EXPOSED TO FIRE

1-6

Slavko Zdravkovi , Tomislav Igi , Marina Mijalkovi , Milovan Stanojev DIFFERENCES IN INFLUENCES BY THE SECOND ORDER THEORY DEPENDING ON MEMBERS CROSS SECTIONS

7 - 12

Jelena Rusov, Mirjana Misita MODEL OF DECISION SUPPORT SYSTEM USED FOR ASSESSMENT OF INSURANCE RISK

13 - 20

Filip Zdraveski, Zoran Bogatinoski, Bojana Trajanoska MODELING OF SINGLE-FILLET LAP JOINT IN SOLIDWORKS SIMULATION

21 - 27

Glushkov Alexey Vyacheslavovich, Bartolomey Leonid Adolfovich INFLUENCE OF THE FORM AND SIZE OF THE ISOLATED FOUNDATIONS ON THE STRESS-STRAIN STATE OF THE SOIL BASE

28 - 35

Evgenii Romanov, Yuri Andrianov, Lyudmila Nizova, Anna Nikitina ENGINEERING PERSONNEL TRAINING THROUGH THE EXAMPLE OF VOLGA STATE UNUVERSITY OF TECHNOLOGY, MARI EL, RUSSIA

36 - 43

Mijat Jocovi , Boban Melovi , Nikola Milovi ROLE OF REGULATORY REFORMS FOR DEVELOPMENT AND QUALITY IMPROVEMENT OF THE CONSTRUCTION SECTOR IN MONTENEGRO

46 - 53

Maria Francesca Milazzo ON THE IMPORTANCE OF MANAGERIAL AND ORGANISATIONAL VARIABLES IN THE QUANTITATIVE RISK ASSESSMENT

54 - 60

Polukhina A.N., Rukomoinikova V.P. DEVELOPMENT OF CLUSTER APPROACH IN TOURISM (RUSSIA CASE STUDY)

61 - 67

Rukomoinikova V.P., Zykova N.N.,Tumbaeva I.D. PRACTICAL ASPECTS OF REALIZATION OF THE DEVELOPMENT STRATEGY IN THE TOURISM REGION

68 - 74

A. Meena Kowshalya, M.L.Valarmathi DETECTION OF SYBIL S ACROSS COMMUNITIES OVER SOCIAL INTERNET OF THINGS

75 - 83

Olga Miju kovi , Branislav !ori , Biljana epanovi COMBINATION OF PATCH AND WHEEL LOADS ANALYTICAL APPROACH TO PLATE BUCKLING

84 - 92

Journal of Applied Engineering Science 14(2016)1

CONTENTS

Viktor Pukhkal, Andrii Bieliatynskyi, Vera Murgul DESIGNING ENERGY EFFICIENCY GLAZED STRUCTURES WITH COMFORTABLE MICROCLIMATE IN NORTHERN REGION

93 - 101

Marina Rako!evi ANALYTICAL SOLUTION FOR SIMPLY SUPPORTED LAMINATED COMPOSITE 102 - 108 PLATES BASED ON PARTIAL LAYERWISE THEORY Milan Spremi , Zlatko Markovi , Jelena Dobri , Dragan Bu evac SHEAR RESISTANCE OF LONGITUDINAL SHEAR CONNECTION 109 - 114 WITH GROUPS OF HEADED STUDS Ljiljana ugi , Stanko Br!i , piro Gop!evi FREE VIBRATION ANALYSIS OF SPATIAL FRAMES 115 - 120 WITH VARIOUS BOUNDARY CONDITIONS Sergei Bovteev, Svetlana Kanyukova, Vladimir Okrepilov, Anna Rezvaia CONSTRUCTION WORK TASKS DURATION: NEW METHOD 121 - 127 OF ESTIMATION AND QUALITY CONTROL Nenad Fric, Dragan Bu evac, Zoran Mi kovi , Zlatko Markovi ,Jelena Dobri , Milan Spremi 128 - 134 USAGE OF ZINC-SILICATE COATINGS IN FRICTION CONNECTIONS Vladimir Okrepilov, Marina Gravit, Ekaterina Nedviga, Dudnik Oleg EFFECT OF GOODWILL ON THE PERFORMANCE OF THE ORGANIZATION 135 - 139 OF THE CONSTRUCTION SECTOR Sanja Paunovi ari , Veljko Radulovi , Ema Alihod i Ja arovi , Vera Murgul LIGHT REVEALING ARCHITECTURE FORM - THE ROLE OF LIGHT 140 - 147 IN CONTEMPORARY INTERPOLATION Mladen Perazi , Nevenka Pavli!i , Milo Kne evi ACHIEVING GENDER EQUALITY IN EDUCATION 148 - 153 IN CIVIL ENGINEERING IN MONTENEGRO Mikhail Valerievich Shubenkov, Dmitriy Alksandrovich Khomyakov 154 - 162 SPACE OF THE REGIONAL AGGLOMERATIONS AND RE-INDUSTRIALIZATION Ana Trombeva-Gavriloska, Marijana Lazarevska, Meri Cvetkovska EXPERIMENTAL TESTING OF COMPOSITE SANDWICH PANELS 163 - 168 WITH DIFFERENT FACE SHEETS Nada Vignjevi or evi STANDARDS AND COMPETENCIES OF THE EU - THE MARKET STRATEGIES 169 - 178 OF FINANCIAL SERVICES IN THE BALKAN REGION Manuel Alejandro Fernández Ruiz, Luisa Maria Gil-Martin DESIGN OF A COMPRESSION STRUCTURE WITH INNER RIBS USING FORCE 179 - 184 DENSITY METHOD & TOPOLOGICAL MAPPING Journal of Applied Engineering Science 14(2016)1

EDITORIAL

And for the sixth time on the beautiful slopes of Durmitor, in March, there was a collection of Civil Engineering - Science and Practice 2016. And in a year when Montenegro builds its motorway aim of the meeting was to develop a professional future construction.

Prof. dr Milo Kne evi

The world of construction is challenging and provides the opportunities and privileges to those who deal with him, but it requires great effort and many sacrifices.

Horizons of this confference this time is consisted of 215 works signed by authors from 19 countries. We thank the members of the Scientific Committee and authors, and especially the sponsors and friends, representatives of foreign and domestic institutions that have supported us in the organization and help maintain a set GNP 2016. This issue is devoted to selected works from the Conference. Sincerely yours, Prof. dr Milo Kne evi President of the GNP 2016 organisation committe, Faculty of Civil Engineering, University of Montenegro, Podgorica, Montenegro

Journal of Applied Engineering Science 14(2016)1

Professional Paper

doi:10.5937/jaes14-6150

Paper number: 14(2016)1, 346, 1 - 6

THE ASSESSMENT AND REPAIR OF THE PRECAST RC STRUCTURE EXPOSED TO FIRE Vlastimir Radonjanin Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia Mirjana Male ev Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia Ivan Luki# Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia Slobodan upi# Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia Suzana Vukoslav"evi# Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia This paper presents the assessment and repair of precast RC structure exposed to fire in Novi Sad. Detailed visual inspection, which includes described and classified damages and defects of RC columns and beams, is presented in the paper. Control design of the built-in concrete and reinforcement, as well as geodetic survey and conclusion on the state of the structure, are carried out. Two possible repair solutions were analysed. Key words: RC structure, Fire, Visual inspection, Control design, Repair INTRODUCTION On May 5th 2013. there was a fire in production hall-building Uradi sam in Novi Sad. Major interior parts with installations, roof coverings and facade s cladding, as well as complete roof-bearing structure have been destroyed during the fire. RC columns and RC facade beams have suffered serious damages. Object s appearances before and after fire and clearing the ground off, are presented in Figures 1 and 2. Figure 2: Object s appearance after fire and clearing the ground off

VISUAL INSPECTION AND ANALYSE OF DETECTED DEFECTS AND DAMAGES

Figure 1: Object s appearance before fire

Detailed visual inspection of all RC columns and beams, as well as measuring of dimensions, in order to compare them with the originals, have been made. During the detailed visual inspection of the elements, following defects and damages were registered: insufficient protective concrete layer, rough concrete surfaces,

*University of Novi Sad, Faculty of Technical Sciences, Trg Dositeja Obradovi a, 21000 Novi Sad, Serbia; radonv@uns.ac.rs

Vlastimir Radonjanin - The assessment and repair of the precast RC structure exposed to fire

spalled, fallen off or burnt concrete protection layer, changed surface concrete s colour, crumbly and burnt concrete protective layer with aggregate grains of changed colour, crumbly longitudinal column edges, net-like fissures on the surface of the elements, horizontal cracks along stirrups, horizontal cracks due to flexion of columns, vertical cracks and gapes along column edges (along main reinforcement), breaking, spalling and falling of concrete along the edge of columns, the impaired adhesion between concrete and reinforcement, exposed reinforcement, local mechanical damages of concrete on places where interior elements were fixed. Characteristic defects and damages after fire are presented in figures 3 to 7.

Figure 5: Horizontal cracks due to flexion of column (during the collapse of roof structure)

Figure 6: Crumbling of concrete in the supporting zone, peeling of surface and protective concrete layers, deformed stirrups and anchors, change in aggregate colour

Figure 3:Cracking, separation and peeling of concrete along the column edges (up to the main longitudinal reinforcement), pronounced change in aggregate colour, net-like fissures Figure 7: Beam rotation (tends to decline)

SUBSEQUENT QUALITY CONTROL OF BUILT-IN CONCRETE

Figure 4: Peeling of crumbly protective layer of concrete, visible reinforcement

In order to determine actual compressive strength of concrete after fire, concrete samples (concrete cylinders) are taken from basic structure elements: columns, beams and floor slab. Cylinders are used to evaluate compressive strength of concrete, as well as to determine the depth of burnt concrete layer and detect internal cracks. Compressive strength of concrete cylinders, recalculated to compressive strengths of concrete cubes with 20cm edge, are presented in Table 1. Journal of Applied Engineering Science 14(2016)1, 346

Vlastimir Radonjanin - The assessment and repair of the precast RC structure exposed to fire

After detailed analyze and evaluation of compressive strength of concrete after fire, it was concluded that compact concrete core exists in all of the RC elements, it has satisfactory mechanical properties and designed compressive strength class C35/45. SUBSEQUENT QUALITY CONTROL OF BUILT-IN REINFORCEMENT Samples of ribbed reinforcement are taken to determine the quality of reinforcement after fire. Reinforcement bars were taken from RC beam Â&#x2013; binding rafter, which remained standing after

clearing the demolished roof structure. Tensile strength, yield strength and unit breaking elongation were determined during the laboratory examination. Results are presented in Table 2. GEODETIC SURVEY OF THE VERTICALITY OF THE COLUMNS Geodetic survey, which included eleven spots on every column, was realised. Schematic display of movement of the top of the column in relation to vertical axis, is presented in the Figure 8.

Table 1: Basic statistical parameters for assessment of compressive strength of concrete

Element

Mean value of compressive strength (MPa) 59.2 56.5 44.4 44.7 58.7

Number of cylinders

RC columns, axis A RC columns, axis B RC beams, axis A RC beams, axis B RC floor slab

5 5 3 3 3

Min. value of compressive strength (MPa) 52.7 47.4 39.4 37.3 55.7

Table 2: Mechanical characteristics of examined reinforcement samples

Sample dimensions (mm) D1 18 D2 18 D3 18 G1 18 G2 18 G3 18 Min. (SRPS C.K6.020)

Sample mark

Yield strength Rp (MPa)

Tensile strength Rm (MPa)

Unit breaking elongation A (%)

463 440 447 482 505 482 400

552 525 526 546 577 550 500

13,3 14 14,4 10 10

Figure 8: Schematic display of movement of the top of the column in relation to vertical axis

Journal of Applied Engineering Science 14(2016)1, 346

Vlastimir Radonjanin - The assessment and repair of the precast RC structure exposed to fire

Columns A3, A5, A6 and A7 are evidently inclined towards the interior of the hall. Deviations of top parts of these columns in relation to fixed part of the column, i.e. in relation to the axis of non-deformed column, are great and are between 71185 mm. Most of the columns were not deformed, nor was there excess of tension due to bending, because the main roof carrier fell from their supports relatively fast. However, on columns A3, A5, A6 and A7 connection between anchors on the top of the column and main roof carriers broke only after columns started to bend. CONCLUSION ON THE STATE OF THE STRUCTURE During the fire, which occurred in the building hall Uradi Sam in Novi Sad, major interior parts with installations, roof coverings and facade s cladding, as well as complete roof-bearing structure have been destroyed during the fire. Remaining elements of the bearing structure RC columns and RC facade beams suffered serious damages, while the floor slab had just surface damages. Mechanical properties of the built-in materials: concrete and reinforcement haven t been reduced after fire. Degree and nature of damage of the elements caused by fire had such an influence on the structure, that structure load bearing capacity is reduced at all the RC columns and beams, while stability is compromised at some of them. REPAIR SOLUTIONS Two possible repair solutions were analyzed. Variant I includes repair of RC columns, while variant II includes removal of existing and concreting the new RC columns. Both methods predict removal of existing facade RC beams, which suffered serious damages during the fire. Variant I Repair solution includes: removing crumbly and burnt concrete all over the columns; complete removal of protective concrete layer in upper part of the columns (internal cracks and segregation have been registered there); cleansing the uncovered reinforcement from traces of corrosion; local reprofiling of crumbly and detached 4

longitudinal edges of the columns (until the designed dimensions are accomplished) with micro-reinforced repair mortar; strengthening the columns with additional stirrups; local repair of crumbly, cracked and burnt parts of columns and concreting new protective layer in upper parts of the columns. Manual or machine chiselling of cracked, loose and burnt concrete is needed at all columns. Chiselling is continued until all of the crumbly parts are removed. Plan of making the slits, where new stirrups are confined, as well as new cross section of rapaired column, are presented in Figure 9. Variant II Second variant includes: removal of the upper parts above 2m of every column; chiselling of concrete and uncovering the reinforcement above 1.5m of every column; cleansing the uncovered reinforcement from traces of corrosion, placing the new reinforcement and bonding it with existing one; planking and concreting new columns. Diamond wire can be used to cut and remove upper parts of the columns. In order to provide enough space to bond existing and new reinforcement, chiselling of concrete is scheduled above 1.5m of every column up to 2m, where columns have been previously cut with the wire. Further actions of this solution include: manual or machine chiselling of cracked, crumbly and burnt concrete below 1.5m of every column; cleansing the uncovered reinforcement from traces of corrosion; cleaning and washing chiselled concrete; placing the new longitudinal reinforcement and bonding it with existing one using electric welding; strengthening the longitudinal reinforcement with new stirrups !8/15 in the middle and !8/7.5 in the upper part of every column, planking and concreting new columns (figure 10). CONCLUSION If we want to compare these two solutions from the economic point of view, detailed techno-economic analyse is needed. However, taking scope of work, disposable materials and experts into account, second method has some advantages, especially considering this: removing the columns can be performed in a short period of time, Journal of Applied Engineering Science 14(2016)1, 346

Vlastimir Radonjanin - The assessment and repair of the precast RC structure exposed to fire

because they stand free and unbonded with other elements; repair techniques and strengthening of damaged RC elements require special materials, equipment and methods, which take considerably more time; a lot of companies are able to perform classical construction works, while repair methods and strengthening of elements belong to the group of specialized works, which only some

of the companies are capable of. On the other hand, first variant has the advantages in terms of consumption of concrete and reinforcement. Table 3 presents selection of variants with various aspects.

Figure 9: Details of the repair of RC columns

Figure 10: Concreting the new column Table 3: Variant selection with various aspects Variant selection Scope of work

Variant II

Duration of works

Variant II

Consumption of concrete

Variant I

Consumption of reinforcement

Variant I

Disposable materials

Variant II

Disposable companies

Variant II

Journal of Applied Engineering Science 14(2016)1, 346

Vlastimir Radonjanin - The assessment and repair of the precast RC structure exposed to fire

REFERENCES 1) Concrete Repair Manual, Second Edition, Volume 1 and 2, ACI, pp.2093, 2003. 2) Elaborat o kvalitetu materijala ugra!enog u konstrukciju proizvodne hale TEHNOBIRO (gra!evinski dnevnik i izve taji o ispitivanju ugra!enih materijala) 3) Eropean Standards for Repair and Protection of Concrete, Huwel Davies Consultancy, 2001. 4) Glavni arhitektonski projekat - Preduze"e za proizvodnju, izgradnju, rekonstrukciju, projektovanje i trgovinu na veliko i malo, P.O. TIPING doo - Beograd

5) Glavni projekat konstrukcije - Preduze"e za projektovanje i konsalting BMSK doo Beograd 6) Monitoring and Assessment of structures, G.S.T. Armer, New York, Spon Press, pp. 167, 2001. 7) Structural Design for Fire Safety, Andrew H. Buchanan, Wiley, pp.421, 2002. 8) V. Radonjanin, M. Male ev: Materijal sa predavanja iz predmeta Trajnost i procjena stanja betonskih konstrukcija i Sanacija betonskih konstrukcija Paper sent to revision: 26.05.2014. Paper ready for publication: 01.02.2016.

Journal of Applied Engineering Science 14(2016)1, 346

Review Paper

doi:10.5937/jaes14-7659

Paper number: 14(2016)1, 347, 7 - 12

DIFFERENCES IN INFLUENCES BY THE SECOND ORDER THEORY DEPENDING ON MEMBERS CROSS SECTIONS Slavko Zdravkovi# Faculty of Civil Engineering and Architecture, University of Nis, Serbia Tomislav Igi# Faculty of Civil Engineering and Architecture, University of Nis, Serbia Marina Mijalkovi# Faculty of Civil Engineering and Architecture, University of Nis, Serbia Milovan Stanojev Faculty of Civil Engineering and Architecture, University of Nis, Serbia In this paper Second order theory is derived from deformation method. In given numerical examples (1 and 2) it has been shown that for the same values of normal forces in members, for the same lengths of the members of the system and for the same modulus of elasticity E, but for the different dimensions of cross sections, very different influences are obtained. Calculated values of bending moments differ very little, if the cross section of the member system is closer to real value, than that of the cross-section of members which are closer to the system stability limit. The greater the member rigidity, the smaller the differences in influences and displacements calculated according to linearized and accurate Second order theory. Key words: Second order theory, Members, Cross sections INTRODUCTION First order theory, i.e. linear structural statics, such as is used in everyday engineering practice, is based on three basic assumptions [01]: 1. Assumption that the strain of ! axis of the member and rotation " of the cross section of the member, and their derivations are small values whose squares and higher powers can be neglected. Therefore, this assumption considers !<<1 and "<<1. For this reason, it is called the assumption of small deformations. This assumption provides geometrical linearity in solving the tasks of structural statics. 2. Assumption that the values of displacement of the impact points of external forces on the girder and internal forces are small in respect to the basic dimensions of the girder. For this reason it is called the assumptions of small displacement values of impact points of external and internal forces. This assumption provides static linearity, because in the equilibrium conditions, the displacements of impact points of the external forces on the girder and of the interior forces

are neglected, that is, the equilibrium conditions are written on the unstrained girder [2]. 3. The assumption of the linear relation between the strain and stress, that is, temperature changes. The assumption provides physical linearity when solving the tasks of structural statics, which set by the Hooke s law [02]. Finite deformation theory rejects first two of the previously laid down assumptions, and retains only the third assumption of the physical linearity of the problem. The second order theory rejects only second of the previously mentioned assumptions, and retains the first and the third assumption. The need not to neglect the displacement of impact points, that is, justifiability of writing the equilibrium conditions on the strained girder will best be observed in the following example.

Figure: 1 Principle of second order theory

*University of Ni , Faculty of Civil Engineering and Architecture, Aleksandra Medvedeva, 18000 Ni , Serbia; milovanstanojev@gmail.com

Slavko Zdravkovi - Differences in influences by the second order theory depending on members cross sections

If we consider the equilibrium of unstrained simple beam, in Figure 1, force S does not affect the values of bending moments in transverse cross sections of the beam. However, by considering the equilibrium of strained simple beam (second order theory), the bending moment in arbitrary cross section [3] has the value: (1) Where Mc0 is the bending moment of the simple beam loaded only by transverse loads. Member S!v can have significant value for higher axial load S even at small deflections. On the other hand, the member S!v causes further increase of deflection of the simple beam, which proportionately increases the value of moment Mc. Therefore, by calculating the simple beam, in Figure 1, according to the linear theory, we reduce the safety coefficients of the girder. LINEARIZED SECOND ORDER THEORY

APPLICATION OF THE STRAIN METHOD IN THE CALCULATION OF THE SYSTEM OF MEMBERS ACCORDING TO THE SECOND ORDER THEORY Basic equations of the strain method The expression for the member restrained at one end is [04]:

M ig = d igji - dig Èig + M ig d ig =

EI w 2 sinw × L sinw - w cosw

(4) (5)

where:

The system of equations according to the second order theory can be linearized, at least according to the unknown parameters, starting from the assumption that the product of static and strain unknown is equal to the product of the same unknowns [4], where the static unknown is determined according to the linear theory: (2) In this way, the linearized theory of second order is obtained, whose equation system is: (3.a) (3.b) (3.c) (3.d) (3.e) (3.f) (3.g) If it is the case of one straight member with set limit conditions, then we can determine force H, so the problem of nonlinearity is solved. For the problems of member systems, determination of normal forces cannot be separated from the de8

termination of transversal forces, and in turn, they depend on the moments in the adjacent members. Therefore, instead of force H force H0 is adopted. According to the second order theory, the system equilibrium is established on the strained system, which actually happens in reality.

Apart from the members restrained on both ends and one end, in the second order theory the concept of elastically restrained consoles is introduced. Rotation of the node "i in which such member is restrained, changes the restriction moment. The expression for the moment on the end i, of the console is, can be written in the form: (6) Parameters dig and eis are calculated of one determinate value of axial force S, due to the limited validity of the superposition principle. The rigid restrainment is: (7) Conditional equations for determination of strain Indeterminate parameters With the expression 4 and 5 we defined the moments of so called ,,g type members and ,,s type console members according to the second order theory [3]. The number of strain indeterminate parameters is equal to m+n, where m is the number of unknown rotations of nodes "i(i=1,2, ,m), and nis the number of degrees of freedom #j (j=1,2, ,n) of the system grid. The concept angles of node rotation whose number is equal to the number of groups of rigidly connected members), as well as the notion of the system grid were introduced in Journal of Applied Engineering Science 14(2016)1, 347

Slavko Zdravkovi - Differences in influences by the second order theory depending on members cross sections

the approximate strain method according to the first order theory. Whereby the number of unknown displacement parameters !j (j=1,2, ,n) is determined by static kinematic considerations in the system called the grid of the given girder, and it is equal to the number of degrees of freedom of displacement of this grid. (8) (9) (10) (11) Where the coefficients of the members are functions of the characteristical cross-sections, spans and values of axial forces of members, while in linear theory, those were constants of the members with the constant cross-sections. For determination of all strain unknowns, a mequation of rotation of nodes with rigid angles should be composed, as well as n equation of displacement of joint figures. Conditional equations for determination of strain indeterminate parameters If in the equations of node rotations which have rigid angles, which formally do not differ from the equations in linear theory, since the equilibrium of moments of all nodes is required, the expression for moments on the ends of members are included, we will obtain a system of m-equations with m+n deformation unknown values "i and !j: (12)

we will conclude that the influences according to the second order theory can be determined according to the linear theory [02], if the considered element of the member, is subjected also to the action of fictitious distributed moments, apart from the given load. (13) Linearization of the task is performed by simplification according to which the axial force H=Ho is determined from the linear theory task, or even from the figure of joints if it can be even in the precarious equilibrium with the set external forces. For the value of work of distributed fictitious moments mf on the displacements !j the following is obtained: (14) Whereby the + sign should be assumed when N(o,ab) is negative, provided that in the sum #ab there are not console members ne (type s) included. When in the displacement equations the expressions for the moments on the ends of the members are included, as well as the expression for the work of distributed moments, then the following form of the displacement equation is obtained: (15) In equations 14 and 15 the moments on the ends of the ,,g type members and ,,s type members expressed by m+n indeterminate (unknown) deformation values "i (i=1,2, ,m) and !j (j=1,2, ,n), are unknown and they will be determined from the m+n conditional equations. These conditional equations, as opposed to the first order theory, should be written now on the strained girder. By introducing the following designations [06]: (16)

Displacement equations When writing the equations, we make a requirement that the algebraic sum of works of all external forces on each virtual displacement of the joint figure is equal to zero, whereby displacement of impact points of external forces must not be neglected. By comparing the basic equations of equilibrium of differential element of the member written in the second order theory and the linear theory [03], Journal of Applied Engineering Science 14(2016)1, 347

(17)

(18)

Slavko ZdravkoviÂ - Differences in influences by the second order theory depending on members cross sections

(19)

(20)

Normal force values N15=-500 kN N14=-500 kN N12=N23=0 kN

The constant equations, i.e. node rotation equations and displacement equations finally assume the form:

(21)

Member constants dig and eis as well as the restrainment moments , and (accordingly the parameters A0i) in the expressions from 16 to 20 depend on the normal forces in the girder members, while in the first order theory these values did not depend on the normal forces in the girder members. Diagonal elements Aij of the square matrix A contain the constants eis of the ,,sÂ&#x2019;Â&#x2019; type members, which is not the case in the first order theory. In elements Cjl of the matrix C, according to the adopted marking, the new terms

are introduced, which do not exist in the first order theory. Finally, the difference between the first and second order theory reflects in the elements Coj of the matrix Coj, which in the second order theory have the following addition

Figure: 2 Static system

The system is doubly indeterminate in terms of strain (!1 and "1), so the conditional equations are:

The coefficients along the unknowns in the conditional equation are calculated depending on the value #:

NUMERICAL EXAMPLES 1) Let us calculate the values of the bending moment on the ends of the members of the given system, according to the second order theory, if the support 4 is displaced for cv=2 cm downwards. The values in the members should be taken from the grid of the system. a) b/h=25/40cm/cm Figure 3: Displacement status !1=1

Journal of Applied Engineering Science 14(2016)1, 347

Slavko Zdravkovi! - Differences in influences by the second order theory depending on members cross sections

Normal forces values N15=-500kN N14=-500kN N12=N23=0kN The coefficients along the unknowns in the conditional equation are calculated depending on the value !: Figure 4: Figure of nodes

!14=1,291

!15=0,707

!12=!32=0

Conditional equations of the strain method. In order to calculate coefficient A10 and C10 one should determine the rotation angles of the stable figure of joints at displacement cv,4= 2,0cm, and then find the moments of full restraint. Displacement of nodes and rotation of members of the stable joint figure (node figure) are usually find applying VilliotÂ&#x2019;s displacement plan or with poles and medium poles. Conditional equations of the strain method.

1,4645EI"1-0,650EI#1-9,6=0 "1= 14,4596/EI #1= 11,1680/EI -0,650EI"1+1,6068EI#1-3,84=0 Displacement of node 5 is 21,34mm.

Displacement of node 5 is 11,17mm.

Figure 6: Diagram of bending moment

CONCLUSION

Figure 5: Diagram of bending moment

2) For the system given in the example 1 ie. for the same load and lengths of the members, let us calculate the bending moments in the case of various stiffness of all members [01].

Journal of Applied Engineering Science 14(2016)1, 347

In the previously given numerical examples (1 and 2), as already know, it has been shown that for the same values of normal forces in members, for the same lengths of the members of the system and for the same modulus of elasticity E, but for the different dimensions of cross sections, very different influences are obtained, in this case the bending moments at the ends of the members and displacement of cantilever top. The values of bending moments in the restraint (node 3) differ (Fig. 5 and 6) only because of different cross-sections (25/40 and 20/20cm) for 550%. Along the member 2-3 the diagram 11

Slavko Zdravkovi - Differences in influences by the second order theory depending on members cross sections

of bending moment even changes the operator (side of tension) and it differs for 1455%. In case there is no displacement of support 4 for 2cm the difference in node 1 is 31,93%, and the bending moments along the member 2-3 the operator is changed. Difference between displacements of node 5 in case 1 and in case 2 is 191%. The greater the member rigidity, the smaller the differences in the influences calculated according to linearized and accurate Second order theory. ACKNOWLEDGEMENTS This research is conducted at Faculty of Civil Engineering and Architecture of University of Ni in the framework of the Project in the field of technological development in the period 2011-2014 (TR 36016 and TR 36028), financially supported by the Ministry of Education, Science and Tehnological development of the Republic of Serbia.

REFERENCES 1) !au evi", M., & Buli", M. (2013). Stability of structures. Zagreb: Golden marketing. 2) !au evi", M., Zdravkovi", S., & Mund i", E. (1992). Statika i stabilnost konstrukcija po teoriji drugog reda. Sarajevo: Svjetlost. 3) #uri", M. (1973). Stabilnost i dinamika konstrukcija. Beograd: Skriptarnica Saveza studenata Gra$evinskog fakulteta. 4) #uri", M., & Jovanovi", P. (2002). Teorija okvirnih konstrukcija. Beograd: Gra$evinska knjiga. Paper sent to revision: 02.02.2015. Paper ready for publication: 01.02.2016.

Journal of Applied Engineering Science 14(2016)1, 347

Original Scientific Paper

doi:10.5937/jaes14-8845

Paper number: 14(2016)1, 348,13 - 20

MODEL OF DECISION SUPPORT SYSTEM USED FOR ASSESSMENT OF INSURANCE RISK Jelena Rusov Dunav Insurance Company ado Belgrade Mirjana Misita University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia In order to run a modern business in uncertain times, business forcasting is very important for evaluation of companyÂ&#x2019;s future financial performance. This paper shows an example of premium forecast based on the assessment of risk sources in insurance system. Due to uncertainty that is one of the characteristics of loss occurrence and indemnity amount, it is important to hold sufficient assets to cover the risk. For asset-liability matching, one should first assess the impact of risk on premium movement per insurance lines. This is the main concept of development and performance of insurance companies. This paper shows an experimental research of risk ranking based on projected model of decision support system. Decision support system is used with the aim to generate hierarchy of influential criteria and alternatives of risk assessment model for stated insurance lines. Suggested model supports the idea according to which one should first determine insurance lines with the highest risk and then, on that basis, make a decision on premium amount in the following period. Key words: Forecast, AHP, Risk assessment INTRODUCTION Using relationship between the values of income, expenses and profit to define business objectives is one of the main goals of business forecast in a certain period of time. Analysis of business forecast seeks to determine potentially critical periods which would require additional funding in order to secure continuous business operations. Monitoring and forecasting of policy sale flow (premium) is very important for securing enough assets to cover the risk, meet the expenses and make profit. Forecasting of financial results is a basic development concept and one of the characteristics of insurance company operations. Forecasting stabilizes business operations, growth and development and improves the insurance market. In addition, it also provides complete protection of insuredÂ&#x2019;s interests. Global movement and its influence on narrow and underdeveloped Serbian market, are undoubtedly very risky for company operations. In order to avoid, anticipate, reduce or mitigate the risks, the company should first perform risk identification, analysis and assessment. A growing internationalization and concentration of insurance operations, emergence of new and *Dunav Insurance Company ado Belgrade, 11000 Belgrade, Serbia; jrusov@gmail.com

dispersion of the existing risks call for a clear definition of solvency risk management policy in every insurance company. Risk represents the probability for occurrence of adverse effects on business and financial result and position of insurance company, while risk management is defined as the process of risk identification, measurement, assessment and control. Financial position and solvency of an insurer depend on insurance premium amount. Analysis of insurance company operations and significance of business results forecasting were considered by Gestel et al. [04]. SĂĄnchez used fuzzy regression to forecast one of the main expenses of insurance companies - claim reservation [8]. In addition, Shapiro [9] and Lemaire [6] pointed out the importance and application of fuzzy logic in insurance. Chin-Sheng Huang et al. used AHP and fuzzy logic to suggest an assessment model when buying the policy of life or pension insurance since those insurance lines are among the major individual insurance lines [2]. Model was developed on the basis of experience of 5 insurance consultants, with minimum 3 years experience in insurance companies, where the inputs were: age, annual income, education and risk. 13

Jelena Rusov - Model of decision support system used for assessment of insurance risk

AHP model is developed on the basis of questionnaire which contains expert s opinions regarding these two insurance lines. Fuzzy logic is used to form mapping of inputs, while AHP is used to generate weighted parameters for assessment model. Model from this study might be used to eliminate subjectivity of policy salespersons when making an offer to their clients. Fouladvand and Darooneh used an example of motor vehicle insurance to formulate the model for forecast of insurance company annual income based on premium [3]. Model shows the premium amount when a company operates at a deficit. In addition, it provides detailed statistical analysis of company financial standing. Naimely, collected premium has to be sufficient to cover the insurance indemnity, cost of insurance service provision as well as realized profit. Also, the model predicts realized profit depending on the corresponding risk and premium amount. In addition, the model gives quanitified risk assessment based on premium increase. The link between the longterm company profit and insurance indicators, especially premium, is illustrated based on the obtained results. This paper [7] shows an efficient use of intelligent systems for problem solving in voluntary health insurance. The model is based on neurofuzzy inference system (ANFIS) and it enables efficient determination of risk amount based on the interpretation of health factors of potential insureds with the set of fuzzy rules. Based on health factors such as age, occupation, history of disease, habits (smoker, alcohol consumer) and the like, it is possible to determine the risk of potential insured and consequently, the insurer would be able to determine the amount of insurance premium. Model determines the exposure of a potential insured to risk and that can be very useful for the insurers since they can determine the risk amount and consequently, the premium amount per policy. Backovi! and Babi! showed in practice how successful AHP method might be for reaching optimal decision regarding the selection of the most afordable life insurance policy [1]. Model provides numerous possibilities, therefore, alternatives might be compared per one criterion or few criteria, depending on the decision maker preferences. Also, insurance companies might use the model to make a comparison with the competition, as well as to discover its own weaknesses 14

that should be improved in order to attract the clients. This paper shows that multi-criteria analysis, when selecting the most afordable insurance policy, undoubtedly provides a solution based on the authentic data from insurance companies. DEVELOPING RISK ASSESSMENT MODEL AND INSURANCE PREMIUM FORECAST An insurance company has to monitor risks per insurance lines (life and non-life insurance). Measuring, i.e. risk assessment, should be done by the insurer through qualitative and quantitative assessment of identified risks and events. The risks should be classified according to their impact on overall risk. When an insurance company sells the policy, it grants that it is able to assume the risk through its technical and financial capacities. Risk management implies identification, measurement, assessment and control of risk in company operations. In order to provide company solvency, i.e. in order to enable the company to provide adequate indemnity for all claims, it is necessary to manage the risks in a manner that would provide general and preventive risk identification and permanent maintenance of a degree of risk exposures which is not threatening to property and business operations. Therefore, this paper deals with forecast and profit management through the application of basic risks present on the market. Forecast and profit management are directly dependant on policy sales per insurance lines. Basic risk groups included in the model are the following: insurance risk (R1), market risk (R2), fraud risk (R3), solvency and liquidity risk (R4), legal risk (R5) and environment risk (R6). Each of the aforementioned risks includes a set of subrisks, defined by the Rulebook on insurance company risk management /9/, which are graded and included in weighted grade of the stated risk. Within the basic risk group there is a set of subrisks that are being separately assessed. Regarding the insurance risk, the following risks are explained in details: risk of inadequate insurance premium level (R11), risk of inadequate assessment of the insured risk Journal of Applied Engineering Science 14(2016)1, 348

Jelena Rusov - Model of decision support system used for assessment of insurance risk

(R12), risk of inadequately set retention limit of the company (R13), risk of unmatched and damaging tariff policy of the company regarding risk dispersion (R14), risk of inadequate specification of insurance terms (R15) and risk of inadequate allocation of technical reserves (R16). The second group of risks is divided into the competition risk regarding the premium amount scope of cover (R21) and the risk of disloyal competition when participating in public tender biddings (R22). The risk of fraud, the third group of risks, is divided into the risk of assessment, settlement and

indemnity payment (R31) and risk of collection of recourse and other debts (R32). Legal risk means the risk of losses arising from insurance and other disputes, failure to collect debt and other risks. Regarding the abovementioned subgroups, only subrisks that relate to risk of inadequately defined insurance premium are further divided. Given that all the necessary risks are defined, decision support system is used to develop decision model. Figure 1 shows the hierarchy structure of risk source.

Figure 1: Hierarchy for risk assessment used for insurance premium forecasting

After having defined the hierarchical structure, it is important to assess the risk impact on insurance lines that are being analyzed: 01 Accident Insurance, 02 Voluntary Health Insurance, 03 Motor Vehicle Insurance, 07 Goods in Transit Insurance, 08 Property Insurance against Fire and Allied perils, 09 Other Property Insurance Lines, 10 Motor Vehicle Liability Insurance, 13 General Liability Insurance, 14 Credit Insurance, 18 Road Assistance Insurance, 20 Life Insurance and 22 Supplementary Insurance along with Life Insurance (according to the Journal of Applied Engineering Science 14(2016)1, 348

Codes of the National Bank of Serbia). Risk levels are determined through the application of matrix model for measuring of identified risks. Model uses, among other things, results obtained through the process of assessment, by applying the corresponding weighting system. Numercal scale is used for allocation of weighted risk assessment, where 1 means low risk while 10 defines extreme risk. Naimely, formed risk matrix consists of columns (insurance lines) and rows (management and financial risks) while the 15

Jelena Rusov - Model of decision support system used for assessment of insurance risk

elements of matrix are numerically defined and they represent assessment of risk impact on insurance lines. The values of defined risks are given based on risk impact on policy sale and premium in the period from 2008 to 2014 with the application of

AHP technique (Analytical Hierarchy Process). AHP is a multi-criteria technique which decomposes the complex problem into a hierarchy. Assessment of alternatives for a specific example of a company Â&#x2013; insurance company, per identified risk sources (R1-R-32) is shown in Table 1.

Table 1: Assessment of risk sources

Journal of Applied Engineering Science 14(2016)1, 348

Jelena Rusov - Model of decision support system used for assessment of insurance risk

Table 1: Assessment of risk sources

RESULTS AND ANALYSIS Application of AHP method generated synthesized results shown in Table 2.

Journal of Applied Engineering Science 14(2016)1, 348

Jelena Rusov - Model of decision support system used for assessment of insurance risk

Table 2: Results: Weighted assessment of insurance lines per risk sources

Risk impact on key insurance lines might be ranked based on the results. According to data from Table 2, it can be concluded that insurance risk Â&#x2013; R1 has the most impact on stated insurance lines, which stems from the assessment of its subrisks. However, a special attention should be paid to liquidity risk Â&#x2013; R4 even though it is not highly ranked. The liquidity risk represents the possibility that the company, due to lack of funds, becomes insolvent and has difficulties paying the indemnity. Therefore, premium collection should be improved in order to mitigate the risk. Figure 2 shows the results i.e. the ranking of 12 insurance lines listed from the most significant to the least significant regarding the first level of criteria (basic risk groups). The figure clearly demonstrates that property insurance lines (08 and 09), with total priority of 0,283 are the dominant ones in relation to other insurance lines, i.e. the majority of stated risks have the strongest impact on those insurance lines. The third place 18

is reserved for Accident insurance with priority of 0,129, while Motor Third Party Liability Insurance is in fourth place. These four types are the dominant ones with the total priority amounting to 54%, which means that those insurance lines make the most part of portfolio, i.e. they have the greatest number of policies and consequently, they have the greatest premium collection. The following diagram shows the structure of risks that have impact on insurance lines, Figure 3. Insurance lines might be considered according to certain risks which brings us to various conclusions. Sensitivity graphs show the degree of significance of a certain insurance line in relation to other lines within the model. Significance degree is obtained according to the sensitivity of results. The diagram brings us to a conclusion that if we give less significance to a certain risk in relation to other risks, the ranking of insurance lines will be changed in terms of the risks included in the model (as shown in Figure 2). Journal of Applied Engineering Science 14(2016)1, 348

Jelena Rusov - Model of decision support system used for assessment of insurance risk

Figure 2: Ranking of insurance lines according to their significance in terms of first level risks

Figure 3: Percentage share of risk sources per all insurance lines

It is necessary to control basic risks. In order to avoid bad results, it is necessary to make good risk assessment, especially the assessment of first level risks. Sensitivity analysis determines the impact of risks on insurance lines. This analysis shows the impact on policy sale per insurance lines depending on the change of risks used for model assessment. Diagrams allow decision maker to analyse whether within the given assessment, there is a potential overlapping of insurance lines. In case of a slight variation in assessment of significance of certain risk, such overlapping would indicate the change in structure of analysed results. Each of the stated risks is of utmost importance for company operations. In order to prevent operational risks, an insurance company should transfer the assets into various forms of reserves. In this regard, premium is the main source of assets. The risk of model unreliability represents Journal of Applied Engineering Science 14(2016)1, 348

the risk that the expected premium value will be incorrectly determined due to mistakenly selected statistical distribution which approximates the premium flow. The dynamics of risk change that impacts the premium adequacy should be continually monitored. Analysis of the results shows that for the existing risk groups among stated insurance lines, the insurance lines 09, 08, 01, 10, 03 and 13 are expected to have the biggest increase in forecasted premium in the following year. CONCLUSION Insurance companies act as institutional investors in financial system of a country. Risk dispersion is an important segment of their business. Accordingly, this paper analyses prediction mechanisms and demonstrates how their application in insurance companiesÂ&#x2019; operations may decrease the risk of illiquidity. 19

Jelena Rusov - Model of decision support system used for assessment of insurance risk

Decision support system is used to generate the hierarchy of influential criteria and alternatives in the risk assessment model regarding the stated insurance lines. Suggested model supports the idea according to which one should first determine insurance lines with the highest risk and then, on that basis, make a decision on premium amount in the following period.

REFERENCES 1) Backovi!, M., Babi!, S., (2013) Vi ekriterijumska optimizacija postupka izbora najpovoljnije polise ivotnog osiguranja, Economics & Economy,Vol. 1, No. 1, 41-66. 2) Chin-Sheng Huang, Yu-Ju Lin, Che-Chern Lin (2007) An Evaluation Model for Determining Insurance Policy Using AHP and Fuzzy Logic: Case Studies of Life and Annuity Insurances, Proceedings of the 8th WSEAS International Conference on Fuzzy Systems,Vancouver, British Columbia, Canada, June 19-21. 3) Fouladvand E., M., Darooneh, A. H., (2005) Premium Forecasting of an Insurance Company: Automobile Insurance, International Journal

6) 7)

of Modern Physics, Vol. 16, No 3, 377-387. Gestel, T., V., Martens, D., Baesens, B., Feremans, D., Huysmans, J., Vanthienen, J. (2007): Forecasting and analyzing insurance companies ratings, International Journal of Forecasting, Vol. 23, Issue 3, pp. 513-529. http://www.nbs.rs/export/sites/default/internet/latinica/20/sistem_internih_kontrola.pdf, downloaded on 6th March, 2015 Lemaire. J, (1990) Fuzzy Insurance,ASTIN Bulletin 20.1, pp. 33 55. Nidhi A., Vij S. K, (2013) Reckoner for health risk and insurance premium using adaptive neurofuzzy inferences system, Neural Comput & Applic 23, 2121-2128. Sánchez, J., A. (2006) Calculating insurance claim reserves with fuzzy regression, Fuzzy Sets and Systems, Vol. 157, Issue 23, pp. 3091 3108. Shapiro., A., F., (2004) Fuzzy logic in insurance,Insurance: Mathematics and Economics 35.2, pp. 399 424.

Paper sent to revision: 08.12.2015. Paper ready for publication: 15.03.2016.

Journal of Applied Engineering Science 14(2016)1, 348

Original Scientific Paper

doi:10.5937/jaes14-8900

Paper number: 14(2016)1, 349, 21 - 27

MODELING OF SINGLE-FILLET LAP JOINT IN SOLIDWORKS SIMULATION Filip Zdraveski Ss. Cyril and Methodius University, Faculty of Mechanical Engineering, Macedonia Zoran Bogatinoski Ss. Cyril and Methodius University, Faculty of Mechanical Engineering, Macedonia Bojana Trajanoska Ss. Cyril and Methodius University, Faculty of Mechanical Engineering, Macedonia The aim of the work presented in this paper is to show the applicability of Solidworks Simulation module for calculation of welded structural joints. The presentation is performed through a simple model of axially loaded single-fillet lap joint. Solidworks Simulation offers several options for FEM analysis of welded joints. All reasonable options are exploited and their results are compared in this paper. The reference values are used to validate the results of FEM analysis. They are calculated based on formulas described in Eurocode 3 part 8 which refer to design resistance of fillet welds. FEM analysis is conducted in latest version of Solidworks Simulation 2015 and older version 2012. Results obtained in both versions differ from each other under same starting conditions. Finally, the paper provides recommendations for reliability of the Solidworks Simulation to be used as design tool for calculating welded joints. Key words: Welded structure, Design resistance of welded connections, Fillet weld, Finite element method (FEM) INTRODUCTION Generally weld connections can be analysed using clasical analysis [01] or Finite Element Method (FEM). Finite element analysis (FEA) quite accurately identifies the load path [02], which can be difficult using classical analysis in the case of complex structures. FE package SolidWorks Simulation has been used to evaluate the strength of the welded joints [03, 04, 05]. The software allows simulating welded connection using 3D solid or shell models. Choosing the type of model depends on structure complexity. For more complex structures to avoid the convergence problems it is recommended to use shell model. The geometry of the tested specimen has been modeled using

3D solid and shell model. Shell model have been build from the middle surfaces of the solids. Case study is conducted over the single-fillet lap joint shown on Figure 1. The joint is modeled using Weldments command in Solidworks. Weldment structure is designed as single multibody part. Using Weldments command Fillet Bead, fillet weld bead feature is created between two disjoint bodies. Connection between welded bodies and the fillet bead is established simply by choosing Bonded contact pair. In SolidWorks Simulation the fillet bead body can be simulated using solid or beam elements. In case of solid elements Figure 2, the design resistance of weld can be evaluated using common strength criteria eg. Von Mises yield criterion.

Figure 2: Using solid element for fillet bead Figure 1: Single-fillet lap joint * Ss. Cyril and Methodius University, Faculty of Mechanical Engineering, Karpos II bb, 1000 Skopje; filip.zdraveski@mf.edu.mk

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

When fillet weld bead simulation is performed by using beam element, the program automatically according the fillet bead geometry calculates section properties of beam and converts fillet bead in to the beam elements Figure 3.

weld connection command. When modeled in the first way, Mesh control is applied for the fillet weld bead. General mesh parametars are given on Figure 5, while mesh control is shown on Figure 6. It can be concluded that the size of the mesh elements should be at least half of the thickness of the welded bodies. Mesh control should reduce the size of the weld bead elements to half of the general mesh.

Figure 3: Using beam element for fillet bead

In this case the strength of weld can be evaluated using the same common strength criteria for beam elements. The shell models for the simulation of fillet weld bead have been build from the middle surfaces of the solids shown on Figure 4. Using Surface menu command Middle surface it is possible automatically to create the surface model and in SolidWorks Simulation environment build shell model. The gaps obtained using middle surface command is normal phenomenon and should not be filled using Extend surface command. Removing the gaps can negatively influence to the results. To simulate weld in the SolidWorks Simulation environment has to be choose Edge weld connection where as options can be groove, fillet or spot welds. Fillet weld is created by selecting the terminated surface and the surface to which is welded. It can only be applied to perpendicular surfaces. Therefore, auxiliary surface is added to one of the middle surfaces which is shown on Figure 4. The auxiliary surface should be very short to avoid its influence (increasing the stiffness). The axial force equal to 10 kN has been applied as shown on Figure 1.

Figure 4: Middle surfaces from bodies

Figure 5: Creating mesh for fillet weld bead

STATIC CASE STUDY SIMULATION As already explained, there are three main ways to simulate welded joint in Solidworks simulation: (1) all bodies to be solids, (2) the fillet weld bead to be beam while other bodies solids, and (3) instead of bodies to use surfaces and Edge 22

Figure 6: Using mesh control for fillet weld bead Journal of Applied Engineering Science 14(2016)1, 349

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

Figure 7 shows the definition of bodies as solids. This is particularly important for the fillet weld bead if the feature is created with the Weldment command. In this case, the program automatically defines the weld feature as beam element (Figure 3). Contact sets between individual bodies are given in Figure 8. Global Contact is selected to be No penetration.

In the simulation with beam element, mesh size is very important. As the beam is divided into smaller elements, more accurate results are obtained. Therefore, in the considered case, the beam is applied to finest mesh. A third option that can be used for modeling of welded connection is Edge Weld Connector and its built-in tool of Solidworks Simulation specially designed for welds. Figure 10 shows the option Edge weld connector and surfaces that are joined. Here the global contact set is selected Bonded because surfaces are separated with gap. This is shown on Figure 11. The loads in welded joints calculated by FEA are not readily presentable but program automatically according the electrode and welded material strength properties estimates the needed weld size. This is shown on Figure 12 and 13.

Figure 7: Defining all bodies as solids

Figure 8: Defining contact sets between bodies

Figure 10: Edge weld connector for surfaces

Second option to simulate weld joint is to use beam element. Contact sets between beam and bodies are given in Figure 9. Global Contact is selected to be No penetration.

Figure 11: Contact sets between surfaces

Figure 9: Contact sets between beam and bodies

Figure 12: Edge weld results

Journal of Applied Engineering Science 14(2016)1, 349

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

Figure 15a: Von Mises for 2st study case (solids) Figure 13: Stresses and forces in a fillet weld

RESULTS FROM THE SIMULATION CASES Taking into account what has been said so far about Solidworks Simulation, results of the first and second approach for FEA design resistance of fillet weld can be evaluated using common strength criteria eg. Von Mises yield criterion. This is presented on Figure 14 and 15. The results in Figure 14 refer to the solid weld bead, while the results in Figure 15 refer to the fillet weld modeled as beam.

Figure 15b: Von Mises for fillet weld bead (beam)

Figure 16: Simplified stress plot for surfaces Figure 14: Von Mises criterion for 1st study case

When using Edge Weld Connector (EWC), results are given by calculated Â&#x2013; estimated weld size. These are given on Figure 17. Figure 16 shows the simplification that comes with using surfaces as way of modeling the FE structure. Its easy to separate the stresses (eg. axial, bending) which are caused by the load action pattern. This is done only by selecting the layer in which dominant stresses are included. Figure 16 shows only axial stress caused by the external acting force which is dominant in this case. Calculated values for stresses are given on Figure 12 according to European Standard. Ultimate tensile strength of the welded joint is selected to be 600 MPa. Another important note from the simulations is the difference in results that occurs between different versions of Solidworks Simulation. 24

Figure 17: Estimated weld size according EWC

The difference in results shows under same conditions of meshing, restraining and loading. Stress plot follows same pattern, but values are Journal of Applied Engineering Science 14(2016)1, 349

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

lower in case of older version. This is presented on Figure 14 and 18. The location of maximal value is on different place. In general, values in 2012 are lower than values received in Solidworks Simulation 2015. Also, older version gives only automatic transition of mesh between different bodies/parts bonded together. Last remark can be seen when comparing Figure 2 (version 2015) with Figure 19. Figure 19 shows created mesh transition in version 2012 compared to version 2015.

Another concern about the accuracy and therefore usability of the program is the difference in results in that come from different versions of Solildwork Simulation. Based on the simulations, the second method is not recommended for modeling welded connection. The first and third approach gives acceptable results can be simply verified. VERIFICATION OF RESULTS Here, the first following section presents the procedure concerning the determination of resistance welded connection according Euro Code 3 Part 1-8 [6] and in another section calculated results are presented. Design resistance of fillet weld EC 3, 1-8 Considering Euro Code 3 Part 1-8 the design resistance of fillet welds will be sufficient if the following are both satisfied: (1)

Figure 18: Von Mises for 1st case 2012 version

Figure 19: Automatic transition (version 2012)

COMMENTING ON RESULTS In all three cases, simulations show the same pattern of distribution of load through bodies and fillet weld. However results vary depending on the approach that was used for modeling. Most evident difference is seen with the second case when beam element is used to simulate the weld feature. Local maximums have very high values (Figure 15b) compared to other two cases (1 and 3). This values are way above the material strenght. Journal of Applied Engineering Science 14(2016)1, 349

where u fu - is the nominal ultimate tensile strength of the weaker part joined fu=430 MPa; !v is the appropriate correlation factor, for S275JR !v=0.85; "M2 is recommended resistance for connections "M2=1.25. Design resistance of welded connections has been estimated using simplified method for design resistance of fillet weld. Independent of the orientation of the weld throat plane to the applied force, the design resistance per unit length F(w,Rd) , at every point along the filled weld length should be bigger then the resultant of all the forces per unit length transmitted by the weld and satisfies the following criterion: (2) where: F(w,Ed) is the design value of the weld force per unit length; F(w,Rd) is the design weld resistance per unit length; f(vw,d) is the design shear strength of the weld; a effective throat thickness. The design shear strength of the weld f(vw,d) should be determined from (1): (3)

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

The resultant forces per unit length Ln on the weld, F(w,Ed) (Figure 13): (4) where: Fs - shear surface normal force; Fw - shear weld axis force; Fj - joint normal force. The required weld throat thickness a and weld size z for each node on the intersecting edge of the terminated part can be calculated by setting F(w,Ed)=F(w,Rd). For double-sided welds: (5) Verification results Instead of calculating weld throat thickness, comparison is made only with stress caused by dominant axial force (Von Mises stresses equation 1).

Figure 20: Rosettes strain gauges

CONCLUSION

(6)

The single fillet lap joint treated in this paper is specific case because it is asymmetrically loaded welded joint. Its taken as an example on which (7) it was conducted FE analysis as well as verification check according to Eurocode 3 part 8. General conclusions can be summarized in the (8) following list: Solidworks Simulation is an easy tool for fast It may be noted that the calculated value for calculation; stress in the welded joint is significantly different There are three methods by which it can be from the results obtained with FE analysis. modeled welded joint; This can be explained by the fact that the stan There is a difference in the results dependdard does not predict turning moment that occurs ing on which version of the program used; in this asymmetrical welded connection [07, 08]. Most anticipated results were obtained unThe calculation according EC standards neglects der the first method shown in Figure 14; the existance of !II. On the other hand, FE analysis takes into account the distribution of force through The existence of local maxima with a value the solid and this can be seen on Figure 14 18. above the yield poin clearly shows that certain points in the welded joint are above the Given that Solidworks Simulation is a tool for linear limit; linear analysis (up to yield point), and EC standard applies to linear behavior of welded joint, The difference that appears in results bethe decision about which method of modeling tween different versions gives doubt about within Solidworks Simulation is the most accuthe usefulness of the program; rate should be checked through experiment. EC 3 part 3 do not describe the case of unAs an option for experimental analysis is the use symmetrical load, so get significantly lower of strain gauges in the form of rosettes given in values of stresses in the weld which can t be Figure 20, which can determine the direction and use for comparison; intensity of deformation at a certain point of the Finally, based on the research of this paper, its test piece. Thus the results should be compared recommended conducting experimental test for with FE analysis. 26

Journal of Applied Engineering Science 14(2016)1, 349

Filip Zdraveski - Modeling of single-fillet lap joint in Solidworks simulation

verification of the accuracy of one of the 3 methods provided within Solidworks Simulation. REFERENCES 1) Al-Samhan A., Darwish S.M.H., Finite element modeling of weld-bonded joints, Journal of Materials Processing Technology, 2003, (142), p 587 598. 2) EN 1993-1-8 (2005) : Eurocode 3: Design of steel structures - Part 1-8: Design of joints 3) J.M M!"nguez, J. Vogwell, The stress distribution over open and closed welded joints, Engineering Failure Analysis, 10 (1), 2003, p 103-111 4) K.S. Virdi, F.K. Garas, at al., Structural Assessment: The Role of Large and Full-Scale Testing, CRC Press, 1999 5) Michael A. Weaver, P.E., Determination of weld loads and throat requirments using finite elemt analysis with shell element models a comparison with classical analysis, Welding Journal, 1999, 78(4)

Journal of Applied Engineering Science 14(2016)1, 349

6) O. Doerk, W. Fricke , C. Weissenborn, Comparison of different calculation methods for structural stresses at welded joints, International Journal of Fatigue, 25 (2003), pp 359 369 7) P.Griskevicius, M.Urbas, V.Capas, A. Kozlovas, Modeling of welded connections in SolidWorks Simulation, Proceedings of 16th International Conference. Mechanika, 2011 8) R.N. Mhetre, S.G. Jadhav, Finite element analysis of welded joints, International Journal of Instrumentation, Control and Automation (IJICA), 1(3,4), 2012 Paper sent to revision: 02.02.2015. Paper ready for publication: 05.02.2016.

Original Scientific Paper

doi:10.5937/jaes14-9136

Paper number: 14(2016)1, 350, 28 - 35

INFLUENCE OF THE FORM AND SIZE OF THE ISOLATED FOUNDATIONS ON THE STRESS-STRAIN STATE OF THE SOIL BASE Glushkov Alexey Vyacheslavovich Volga State University of Technology, Russia Bartolomey Leonid Adolfovich Volga State University of Technology, Russia This article reviews the investigations of the stress-strain state of the foundation bed under the variously shaped footings. The foundation basis is featured by cohesive and non-cohesive soil. Construction regulations do not allow to estimate the stress-strain state of bases with the complex shape of the bed. The article presents qualitative and quantitative stress-strain state changes of shape modification of the drawings. Research indicates the behavior of soil under the complex form foundation, components of displacements and stress isolines are also presented. special attention is given to the assessment of the scale factor influence on the stress-strain state in the basis of the cross-shaped foundation. This article seems to be interesting to those who work in the field of building construc-tion and geotechnics engineering. Key words: Foundation form, Cruciform, Cross-shaped, Three rayed, Stress-strain analysis, Scale factor INTRODUCTION One of the ways of decrease in a material consumption and increase of the bearing capacity of the foundation is the optimization of the form of spread foundation beds. In the construction practice shallow foundations under the columns are carried out square and rectangular in the plan view. The improvement of the design of such foun-dations is possible by means of optimization of the form of the foundation base. In construction regulations there is no method of calculation of the foundations with a complex form of the base in the plan view, so the problem of the estimation of the stress-strain state of effective designs of the spread foundations is actual. LITERATURE REVIEW Professor E. A. Sorochan [07] conducted experimental investigations of square and crossshaped footings in a tray of 8x8x8 m in size. In the basis of the foundation sand of an medium fineness and an medium density with e=0,550,65 was used. The results of the tests confirm positive influence of angular cuts of foundation settlements. The replacement of square footings on cross-shaped with identical external sizes allows to reduce the consumption of metal on 26%

and concrete on 15% by the identical load on the foundation. V. P. Ermashov [01] investigated the influence of the cut forms in the reinforced con-crete foundation on the distribution pattern of normal contact stresses along the foun-dation base. As a result, V. P. Ermashov came to a conclusion, that the arrangement of angular cuts in slabs leads to the formation of local zones of a limit state in soil, con-centrating the contact stress in the central part of the foundation base. It allows to re-duce the bending moment in the critical section of the slab and to reduce the material capacity of the foundation. Lightened bearing posts with the use of conic and pyramidal shell constructions were considered by professor A. N. Tetior [08]. From his point of view the best economy of the footing material is the calculation of durability by the limit equilibrium method with the use of the kinematic way, in the principle of which the actual schemes of the collapse of shell construction designs are laid. THE RESULTS OF INVESTIGATIONS Simultaneous accounting of strength and deformative properties of soil in the calcula-tions of the stress-strain state of the foundation with various forms of the foundation was carried out in

*Volga State Universtiy of Technology, 3 Lenin sq., Yoshkar-Ola, Republic of Mari El, Russian Federation, 424000; 256289@list.ru

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

the solution of the three-dimensional elastoplastic issue of FEM (Fi-nite Element Method) with the use of the program PLAXIS. Soil in a prelimit state rep-resents the linearly elastic continuum changing into the limit (plastic) state with the subsequent loading according to the Mohr-Coulomb yield criterion. Calculation is car-ried out with the use of the incremental load stepping. Foundation calculations are made for two characteristic types of the basis: cohesive soil and non-cohesive soil. As cohesive soil soft clay was used (!=18 kN/m3, E=12,0 MPa, "=20 kPa, #=18º); as non-cohesive soil sand of medium fineness and medium density was accepted (!=16,5 kN/m3, E=26,0 MPa, "=1 kPa, #=30º). There was a re-search of the stress-strain state of the basis of the spread foundations of equal square S=4m2=const with the various form of the foundation in the plan: square (model 1), triangular (model 2), three-rayed (model 3), crossshaped (model 4). Settlement models of the foundations are chosen equilateral.

Researches showed that the change of the foundation form in the plan view from square (model 1) to three-rayed (model 3) and cross-shaped (model 4) influences on the stress-strain state of the soil basement. The main results of the research connected with foundation settlements are presented in figure 2a. It is established that the foundation of crossshaped form (model 4) with the pressure of P=400 kPa in cohesive soil is 1,27 times less than the foundation settle-ment of square form (Model 1). It can be seen from the graphs that the settlement of S triangular footing (model 2) with the pressure of P=400 kPa in cohesive soil is 1,06 times less than the foundation settlement of square form, and the settlement of the three-rayed foundation (model 3) is 1,16 times less than the foundation settlement in model 1, respectively. The presence of ledges along the foundation base influences positively on the work of soil in the basis in comparison with the model of square form.

Figure 1: Settlement models of the foundations in the plan view

Figure 2: Settlements from vertical loading of S=f(P) for cohesive (a) and non-cohesive (b) soil with 1 square; 2 triangular; 3 three rayed; 4 cross-shaped foundations

Journal of Applied Engineering Science 14(2016)1, 350

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

In figure 3a isolines of vertical displacements in the basis (cohesive soil) for square (mod-el 1) and cross-shaped (model 4) foundations are given. The transition to the cross-shaped form of the foundation base leads to decrease the size of maximal vertical dis-placements at the level of the base by 1,27 times at P=400 kPa. The width of the de-formation zone for the crossshaped foundation is 1,25 times more, than for the square foundation due to the activating of the more amount of soil in the active zone. At the depth of 0,5b vertical displacements of Uy make 82 mm (model 1) and 63 mm (model 4) respectively (correspondingly). The depth of the deformation zone of the square and crossshaped foundation at P=400 kPa makes 1,82b and 1,76b respectively. Isolines of horizontal displacements of Ux have a closed character. The maximum value of horizontal displacements is located at the distance of (1,10 รท 1,15)b from the foundation axis, at the depth of (0,350,40)b (figure 3b). It is established, the transition from model 1 (square) to model 4 (cross-shaped) at P=400 kPa leads to decrease the maxi-mum horizontal displacements of Ux by 1,39 times.

The analysis of distribution of vertical stresses !y in cohesive soil shows that there is a concentration of stresses in the foundation bed, the maximum values of !y at P=400 kPa for models 1 and 4 make 380,9 kPa and 386,3 kPa respectively. Observation of results (figure 4a) shows that for model 1 and model 4 various distribution pattern and stress decay of !y with the depth takes place. For the cross-shaped foundation stresses of !y are distributed in an active zone on the larger area and quicker fade with the depth. At the depth of 0,75b from the foundation !y value for model 1 decreases by 1,17 times, for model 4 decreases by 1,72 times respectively. The carried out analysis of "xy shearing stress distribution in the basis shows that at P=400 kPa the greatest "xy values for models 1 and 4 have an alternating-sign charac-ter and make 64-68 kPa (figure 4b). Isolines of "xy stresses have a closed character. Maxi-ma of "xy are found at the distance of 0,55b from an axis of the foundations and are localized in the area from the depth of (0,2-0,3)b. In figure 5 one can see distribution of zones of plastic deformations in the basis of square (model 1) and cross-shaped foundations (model 4). Zones

Figure 3: Isolines of vertical (a) and horizontal (b) displacements in the basis of square (model 1) and crossshaped (model 4) foundations for cohesive soil at P=400 kPa

Figure 4: Isolines of vertical (a) and shearing (b) stresses in the basis of square (model 1) and cross-shaped (model 4) foundations for cohesive soil at P=400 kPa

Journal of Applied Engineering Science 14(2016)1, 350

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

of limit state are detected in the area of adjacent the foundation base. For the considered models 1 and 4 at P=400 kPa the width of the area of plastic deformations makes (2,3-2,4)b, the depth of distribu-tion of plastic zones makes 1,9b respectively.

From figure 5 it is visible that the area of distribution of limit state zones in the basis of the cross-shaped foundation is 12-15% less, than for the square form foundation.

Figure 5: Zones of plastic deformations in the basis of square (model 1) and cross-shaped (model 4) foundations for cohersive soil at P=400 kPa

Figure 6: Isolines of vertical displacements at the depth of 0,25b in the basis of calculation models of the foundations for cohesive soil at P=400 kPa Journal of Applied Engineering Science 14(2016)1, 350

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

Figure 7: Isolines of horizontal displacements at the depth of 0,25b in the basis of calculation models of the foundations for cohesive soil at P=400 kPa

Figure 8: Isolines of vertical stress at the depth of 0,25b in the basis of calculation models of the foundations for cohesive soil at P=400 kPa

Journal of Applied Engineering Science 14(2016)1, 350

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

Figure 9: Zones of plastic deformations at the depth of 0,25b in the basis of calculation models of the foundations for cohesive soil at P=400 kPa

Figure 10: Isolines of vertical (a) and horizontal (b) displacements in the basis of square (model 1) and cross-shaped foundations (model 4) at P=400 kPa (non-cohesive soil)

Figure 11: Isolines of vertical (a) and shearing (b) stresses in the basis of square (model 1) and cross-shaped foundations (model 4) at P=400 kPa (non-cohesive soil) Journal of Applied Engineering Science 14(2016)1, 350

Glushkov ALexey Vyacheslavovich - Influence of the form and size of the isolated foundations on the stess-strain state of the soil base

The assessment of influence of the scale factor on the stress-strain state in the basis of the crossshaped foundation is carried out. As a scale factor to overall dimensions of the foundation b index K was used. At K=1,0 the size value of the area of the founda-tion makes K2x !=4,0 m2. Loading settlement distribution S=f(P) of spread cross-shaped foundations at various values of scale factors of K=0,5 (A=1 m2), K=1,0 (A=4 m2), K=2,0 (A=16 m2), to K=5,0 (A=100 m2) for cohesive and non-cohesive type of soil in the basis are given in figure 13. The increase in the area of the cross-shaped foundation leads the settlement S to the essential increase. At the increase of the area A of cross-shaped foundation by 25 times (K=5,0) in the cohesive soil at P=400 kPa the settlement increases by 3,37 times (figure 13a), and in the non-cohesive basis by 3,14 times (figure 13b) respectively.

In the analysis of vertical displacements of Uy it can be seen that the increase in the area of the cross-shaped foundation leads to the proportional reduction of the depth of the deformation zone. At the increase in the area A by 25 times (K=5,0) the deformation zone in cohesive soil decreases from 1,11b to 1,01b at P=400 kPa, in non-cohesive soil from 1,29b to 1,13b respectively. It is established by researches that at the increase in overall dimensions of the crossshaped foundation there is a proportional growth of the maximum horizontal displace-ments of Ux for cohesive soil. So, at P=400 kPa in the cohesive basis the value of Ux max makes 11,6 mm (K=1,0); 22,8 mm (K =2,0); 49,1 mm (K=5,0) respectively. In non-cohesive soil at P=400 kPa there is no such a proportion at the change of the scale factor: Uxmax=6,9 mm (K=1,0); Uxmax=9,1 mm (K=2,0); Uxmax=15,6 mm (K=5,0).

Figure 12: Zones of plastic deformations in the basis of square (model 1) and cross-shaped foundations (model 4) at P=400 kPa (non-cohesive soil)

Figure 13: Dependences of the settlement from vertical loading of S=f (P) for cohesive (a) and non-cohesive (b) soil at various values of the scale index K

Journal of Applied Engineering Science 14(2016)1, 350

Glushkov!ALexey!Vyacheslavovich!-!Influence!of!the!form!and!size!of!the!isolated!foundations on!the!stess-strain!state!of!the!soil!base

The analysis of distribution of plastic deformation zones at P=400 kPa shows that the greatest width of the distribution area makes (1,7-1,9)b at the depth of (0,30-0,40)b for cohesive and noncohesive type of the foundations. The change of the scale index K from 1,0 to 5,0 at P=400 kPa leads to the reduction of the depth of distribution zones of limit balance from 1,40b to 1,14b (cohesive soil); and from 1,77b to 1,15b (non-cohesive soil) respectively. With the loading growth the elastic core having a triangle form under the foundation detects. The height of the elastic core which moves soil apart depends on the value of the scale index K. For non-cohesive soil at P=400 kPa the height of the elastic core makes: h=0,24b (K=1,0); h=0,36b (K=2,0); h=0,53b (K=5,0) respectively. In the cohesive basis the values of h make: h=0,22b (K=1,0); h=0,22b (K=2,0); h=0,28b (K=5,0). RESULTS For the wide use in practice design of nonlinear solutions of soil mechanics it is obvi-ously possible to reveal the influence of factors (!; c; E; ; p; H/b; K) on the deposit of S cross-shaped foundations. As the mathematical model, connecting the size of the cross-shaped foundation settlement with initial parameters, multifactor power dependence is accepted.

0,12 × p1,90 × ( H / b ) × K 1,05 S= E 0,89 × c 0,66 × j 1,49 ×0 ,71 0 ,37

(1)

(cohesive soil)

2441, 06 × p1,60 × ( H / b )

0 , 49

× K 0,82

E1,55 × j 3,31

(2)

(non-cohesive soil) Comparison of the received nonlinear decisions to data of static tests of the founda-tions with various forms of the foundation base [5] indicates their good compliance and possibility of the design of effective foundations with the complex form of the founda-tion base, proceeding from the condition of the maximum allowable settlement.

Journal of Applied Engineering Science 14(2016)1, 350

REFERENCES 1) Ermashov, V.P. (1985) Influence of the foundation form on the distribution of normal contact stresses, Basements, foundations and soil mechanics Vol. 2, p.p. 16-17, Moscow: Stroyizdat 2) Glushkov, A.V., Bartolomey, L.A., Glushkov, V. E. Patent for the invention No. 2529977 (2013) of the Russian Federation The foundation with ledges on the foundation base , Moscow: Rospatent. 3) Glushkov, A.V., Bartolomey, L.A., Glushkov, V.E. (2013) Stress-strain analysis of the oddshaped footings, Materials of the international conference Innovative constructions and materials in foundation engineering and geotechnics , Lipetsk: Paleotip, p.p. 146-151. 4) Glushkov, A.V., Glushkov, V. E. Useful model patent No. 108053 (2011) The cross-shaped foundation with the ledge on the foundation base , Moscow: Rospatent. 5) Glushkov, A.V., Glushkov, V.E. (2014) Stressstrain analysis of the odd-shaped footing soil basement, Modern problems of science and education Vol. 3, http://www.science-education.ru/117-13192 6) Glushkov, V.E, Glushkov, A.V. (2010) Optimization of the foundation base form, Materials of the 5th international conference City Agglomerations in Landslide Territories , Volgograd: VOLGGASU, p.p. 49-52. 7) Sorochan, E.A. (1986) Foundations of industrial buildings, Moscow: Stroyizdat. 8) Tetior, A.N. (2010) Foundations, Moscow: Academy. Paper!sent!to!revision:!28.09.2015. Paper!ready!for!publication:!13.01.2016.!

Review Paper

Paper number: 14(2016)1, 351, 36 - 43

doi:10.5937/jaes14-9399

ENGINEERING PERSONNEL TRAINING THROUGH THE EXAMPLE OF VOLGA STATE UNUVERSITY OF TECHNOLOGY, MARI EL, RUSSIA Evgenii Romanov* Volga State University of Technology, Yoshkar-Ola, Russia Yuri Andrianov Volga State University of Technology, Yoshkar-Ola, Russia Lyudmila Nizova Volga State University of Technology, Yoshkar-Ola, Russia Anna Nikitina Volga State University of Technology, Yoshkar-Ola, Russia The paper reveals priorities and problems of engineering personnel training through the example of Volga State University of Technology, Mari El, Russia. The article presents the following issues: dynamics of its innovative development, interaction between the university and employers, realization of strategic development programs, innovative infrastructure expansion, increase in activity of scientific students societies, creation of interregional resource and unique centres of shared use. On the basis of monitoring, social research of graduates-engineers and employers interviewing, we summarized experience in the field of interaction between students science and manufacture, elicited the reasons for imbalance of the regional labour market and the market of educational services. The paper determines new dimensions of cooperation between the university and enterprises, including the international level. Key words: Engineer, Science, Manufacture, Student, Higher education institution, Innovative methods of training INTRODUCTION Engineering personnel in conditions of the market economy plays the key role in workforce productivity. Over the last years, in the context of world financial crisis and economic sanctions the Russian Federation has been facing serious problems in such leading economic sectors as industry, civil engineering and agriculture. Taking this into account, the president of the country V.V. Putin in his article Formation of justice. Social policy for Russia thoroughly revealed the role of specialists in the social: An engineer, an agriculturist, an economist, a designer each of these professionals must have a possibility not only to get occupational work, but built his professional career. It means the ability to upgrade skills constantly and learn new applied technologies. [02]. At all times regardless of geographical position and regime of any state, in all the time and era, regardless of geography and public, a citizen with engineering education has been always in demand at the labour market. Scientific papers of many foreign and Russian scientists were de-

voted to this problem. According to the famous German physicist A. Einstein: Scientists study already existing things; engineers create things that have never existed before [03]. A British public leader M. Thatcher believed that An engineer is a person who can explain how this or that device works [04]. Labour Organization pays close attention to the issues of professional personnel training: an expression vocational and technical education means theoretical and practical training that has take place at schools with the view of vocational education [05]. RESEARCH RESULTS A retrospective analysis of the engineering personnel training in the Republic of Mari El shows that the source of manpower is Volga State Technical University. Its main mission: An engineer lives in every person . According to the head of VSTU E.M. Romanov, Connection of education with real manufacture is an important step for the economy strengthening [06].

* Volga State University of Technology, Yoshkar-Ola, Russian Federation; RomanovEM@volgatech.net

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

The university has greatly evolved: if in the period of its creation (Volga Forestry Institute) it trained engineering personnel only for the timber processing complex, during 1960-1980th (Mari Polytechnic Institute named after A.M. Gorky) it expanded a number of professions: civil engineers, mechanics, radio engineers and others. Starting from 2012 (Volga State University of Technology), at the stage of transition to the innovative economy, engineering personnel training for industrial, building and agricultural complexes has become more profound. This points to the fact that not only the names of the university underwent changes, but the education system in a

part of engineering personnel training as well. In that regard we rally the opinion of !"#"$# Tale Geramitcioski that Â&#x201C;The education system is the key factor that should establish a solid structure and organization to enable its functional connection with the labour marketÂ&#x201D; [07]. A monitoring survey showed that within the 3 last years the university saw an increase in graduates (bachelors and specialists) of engineering professions (figure1). In view of majors, most of specialists are the engineers of forestry, construction and information technologies, who are much-in-demand at the regional labour market (Figure 2).

Figure 1: Dynamics of the training of engineers at VSTU (number of people).

Figure 2: Grading of actual number of graduates-engineers according to majors (number of people)

Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

However, according to the research, there still exist employment problems even in view of positive dynamics of personnel training. In addition, according to the author s sociological research end the students opinion, the main reasons for this are : low wages (48,8%), remoteness of the work place from the place of residence (18,7%), inconformity with employers demands (9,3%), lack of occupational work places (23,2%) (figure3). According to employers (interviewing), the main problems in the training of engineering personnel are: lack of organizational mechanisms which allow educational institutions interacting with employers regarding to the prognosis of personnel demands;

lack of the state order for specialists training in compliance with labour market demands; lagging of material- technical and practical training bases of educational institutions from demands of modern highly technological manufacture; lack of due motivation of young people to get engineering professions; unfavourable demographic situation in the period from 2001 till 2015 led to the reduction of the school leavers number for 30% (Figure 4)

Figure 3: Grading of opinion of VSTU graduates-engineers about the problems of employment

Figure 4: Grading of employers opinion about the training of engineering personnel

Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

Taking into account these facts, Volga State Technical University has taken a course toward high quality training of specialists and increase of labour motivation (and this is the most important thing) rather than toward positive dynamics of the students number. For these purposes there appeared a lot of innovative methods of training: DEVELOPMENT OF SCIENTIFIC-RESEARCH WORK AMONG STUDENTS The university has powerful scientific potential that includes 9 research-educational centers on the base of scientific schools, technological park, business incubator, students construction department, 7 laboratories open in consort with institutions of Russian Academy of Sciences and Russian academy of Agricultural Sciences, 25 small-scale innovative enterprises, botanic garden-institute, scientific-experimental forestry station. VSTU possesses 86% of all objects of intellectual property in the Republic of Mari El which takes the leading position in this sphere in Volga Federal District. Small-scale innovative enterprises (SIE) are the prototypes of streamlined production works. Every second work place in SIE is occupied by students that is a good base for scientific activity and work practice. One of the examples of practical significance of SIE is that almost all protective coverings for metal dental prostheses in Mari El are laid at the enterprise Examples of practical importance for the Republic of SIE consists in the fact that almost all of the protective coatings on metal dentures in Mari El are applied in the enterprise Poisk-MarSTU . Besides, it manufactures vacuum installations for application of

extra fine film coatings for the clients not only from Yoshkar-Ola, but from Saint-Petrsburg, Kazan, Perm and others as well. Another SIE, Vozrozhdenie , produces drying chambers for wood material, more than 80 of which are installed at the wood processing plants of the country. We can see development of innovative infrastructure of the university, a start-up of the business incubator, an organized work of 9 business offices for high technological economy sector, small and medium business. It should be also noted the development of scientific students laboratories Mechatronic systems , Laboratory of non-destructive control , Laboratory of off-road means of transport . A great role in the development of the scientificresearch work belongs to research and practice conferences at international, all-Russian and intramural levels. For example, in 2014 the university organized 28 scientific students conferences, VSTU students made 2488 reports and published 1851 scientific papers, 9 of which were edited abroad. In order to involve school students into the scientific-research work, starting from 2012 the university annually organizes youth forum My first step in science . Most works are devoted to the forestry and wood processing industry, economy and agriculture. The main scientific fields of publication activity are presented on the figure 5. Scientific activity of students, postgraduates and young scientists of the university is increased through their participation in the grant program P.Y.S.I.C (participant of the youth scientific innovative contest). According to the total number of winners in 2014, VSTU joined the ranks of the best Russian universities.

Figure 5: Fields of concern of students scientific papers [08] Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

More than 200 projects became winners during the whole period of the program s existence. The university pays close attention to the patent activity within the framework of a specially created structural subdivision intellectual property and publication activity . In 2014 there were made 154 applications to the objects of intellectual property, including 104 patents, 65 of them are co-authored by students [08]. During the year of 2024 more than 230 projects were presented to the grant contests, every 5 of which (41 grants) won (figure 6). All these factors contribute to the overall development of the innovation infrastructure of the university as an integral part of the engineering personnel training. Monitoring of the university performance showed that its scientific-research

activity is three times higher than the threshold value (154,81 vs 51,28), international activity 3,7 times ( 3,68 vs 1,0). Moreover, the university exceeded the threshold value in educational activity (62,3 vs 60,0), financial and economic activity (1750,85 vs 1327,57) and employment (99,437 v 98,705) (Figure 7). CONNECTION WITH THE INDUSTRIAL SECTOR This year the university will celebrate 10 years anniversary of the beginning of its strategic cooperation with the machine-building plant. This city-forming enterprise manufactures commercially viable products of the international level. At the plant there are affiliates of three university s departments (radio engineering and communication, information security of automated systems, machine-building and materials science).

Figure 6: Dynamics of students participation in research activity

Figure 7: Results of monitoring of the university activity efficiency

Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

There exists a practice of dual education: every year up to 80 undergraduates, combining work at the plant and studies, get practical experience and apply their knowledge in the process of real manufacture. As the result the plant created a unique Centre of radio-locating system and complexes which solves several tasks: A) Combination of scientific achievements and potential with manufacturing process makes it possible to integrate the activity of already existing and newly created structural subdivisions of the university on the base of the plant, that in its provides necessary infrastructure for the personnel training program. At the same time it is expected not only to apply unique educational programs for profound personnel training, but to train interdisciplinary multi-purpose teams for solving practical production problems. In total this centre creates possibilities for extensive use of laboratories and industrial base in the training process, conduction of mutual scientific-research and design and experimental activity under the conditions of real production. B) Training of highly qualified engineering personnel makes use of all the scientific-research potential of the university. Apart from three VSTU affiliates which operate on the plant there are such structures as the centre of automated mechanical engineering, the centre of engineering and industrial design Bioenergy , students construction department. There is also a college called Politechnich where more than 700 students are trained to get blue-collar jobs. C) Graduates of the university are employed at enterprises. Being taught by the centre program, students expand motivation for demonstration of their best qualities, application of their knowledge at production site. Even today students study in the first part of

the day at the plant, and in the afternoon they continue their studies at the university. The system of dual education is used with regard to the German experience. During university days students are involved into solving of upto-date production tasks. At the same time an employer can reasonably evaluate students knowledge and its application in practice. The main thing is that the prestige of engineering professions grows and outflows of talented young people decrease. More than 75% of engineering personnel of at the plant are VSTU graduates. Only for the last 5 year at the plant there were created 354 work places for these graduates. (figure 4). A demonstrative example of fixing of graduates at enterprises is LLC Technotech , which is the only enterprise in Russia where there is a unique engineering group consisting for 95% of Volgatech graduates. CONNECTION WITH THE REAL SECTOR OF ECONOMY For these purposes in the university there were created three new large structures: Institute of mechanics and machine building, Institute of forestry and nature management, Institute of civil engineering and architecture. Formation of these institutes is a well-planned, balanced decision focused on maximal approaching of our education and science to the real manufacture. Every new institution is closely connected with a particular economic sector. Their aim is to become the main source of manpower. It will give an option to increase the contribution to the innovative development of the republic and the whole country [06]. In our opinion, creation of these institutes and resources concentration will encourage strengthening of relations between higher education and real manufacture.

Figure 8: Dynamics of graduates-engineers employment at the factory Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

As a result there will be more possibilities for implementation of academic knowledge into practice according to the principle of a closed ring. Getting education and taking part in scientificresearch work, students come to the enterprise and realize their ideas; that causes orders from enterprises to the university. Thus, the ring which includes education, science and manufacture is closed.According to the Head of the Republic of Mari El L.I. Markelov, A lot of our enterprises literally stand in a queue for highly qualified specialists . The training of such personnel is a specific state order to universities. While for young people this is a start in life, a possibility to have good profit after getting a profession . INTERNATIONAL COOPERATION IN TRAINING OF PROFESSIONAL PERSONNEL With the view of training of highly qualified engineering personnel, the university practices interaction with foreign universities and firms (figure 9). Development of scientific-research and innovative activity at the university is annually proved by awards at all-Russian and international levels. For example, every year students take part in International festival of innovations, knowledge and inventions Tesla Fest , Serbia; in Russian-Britain forum inventions and innovative technologies, London; in International showroom of inventions

INOVA , Croatia; in International forum of innovative development Open Innovations and exhibition Open Innovations Exp! and others. CONCLUSION To summarize all mentioned above it should be emphasized that the main trends of engineering personnel training are: participation in programs of innovative development of state corporations; creation of the centre of engineering and industrial design on the base of the university; development of the system of small-scale innovative enterprises as the main form of interaction between the real sector of economy and the innovation infrastructure of the university; employers involvement into the educational process; formation of structural subdivisions at the university and at factories within the framework of governmental-private partnership; strengthening of relations with international scientific society in terms of internship and work practice. All these made it possible for VSTU to join the ranks of 95 leading Russian universities which train highly qualified engineering personnel and participants of the real economy market.

Figure 9: Dynamics of internships and work practice abroad [09]

Journal of Applied Engineering Science 14(2016)1, 351

Evgenii Romanov - Engineering personnel training through the example of Volga State University of Technology, Mari El, Russia

REFERENCES 1) Albert Einstein [electronic resource]. URL: http://chemy.ksc.ru/vyskazyvaniya-o-nauke 2) Geramitchioski T., (2015) Cooperation enterprises -universities-students in Macedonia after Bollogne declaration - conditions, problems, challenges and solutions, Journal of Applied Engineering Science, 13 ( 2), 105-110 3) Leonard Louis Levinson [electronic resource]. URL: http://!"#.com/aforizm/1/448. php 4) Margaret Thatcher [electronic resource]. URL: http://constructorus.ru/aforizmy/vyskazyvaniya-velikix-i-uspeshnyx-lyudej-o-professiyax.html 5) News material about VSTU - http://www.volgatech.net

Journal of Applied Engineering Science 14(2016)1, 351

6) Putin, V.V. (2012) Formation of justice. Social policy for Russia, Komsomolskaya pravda. 13.02.2012 7) Recommendations of International Labour Organization. No 57. About vocational training (1937). 8) Romanov E.M., (2015) We work for the whole country, Vash novyi den, 9. 9) The program of fundamental scientific researches in the Russian Federation for a long-run period (2013 2020 years). Yoshkar-Ola, 2015. Paper sent to revision: 11.05.2015. Paper ready for publication: 11.02.2016.

Original Scientific Paper

doi:10.5937/jaes14-9825

Paper number: 14(2016)1, 352, 46 - 53

ROLE OF REGULATORY REFORMS FOR DEVELOPMENT AND QUALITY IMPROVEMENT OF THE CONSTRUCTION SECTOR IN MONTENEGRO Mijat Jocovi# Faculty of Economics, University of Montenegro, Podgorica, Montenegro Boban Melovi# Faculty of Economics, University of Montenegro, Podgorica, Montenegro Nikola Milovi# Faculty of Economics, University of Montenegro, Podgorica, Montenegro The authors of this paper researched the influence of the quality of the regulatory rules on the construction sector in Montenegro. The authors noticed and clearly pointed out that the significance of construction for, the total economy of Montenegro, its influence on other economic activities and participance in the social gross product of the country entirely justifies the need for constant attention of the politics creators. Key issues in the legal framework which negatively influenced the improvement of competitiveness of this sector and national economy are noticed and clearly pointed out in this paper. As the most significant, the following ones are identified: trend of provisions instability, existence of mutual collision of laws and sublegal acts, regulation of spatial planning, issuing building permits, property registration and system of public procurement. After having analyzed the changes in the regulatory frame and their affect on improving the position of Montenegro on the lists of competitiveness in international organizations, the authors make a general conclusion that necessity of regulatory reform with providing a predictable and functional system is one of the basic preconditions for further development of this sector. Key words: construction, Montenegro, economics, regulatory changes, high quality, building permits, property registration INTRODUCTION In the period after gaining independence, together with speeding up the economic growth, construction becomes one of the main economic activities in Montenegro. Since 2006 up to today, the construction sector approximately participates with 5% in the Gross Domestic Product (hereinafter GDP), and the intention of the creators of the economic policy is that this sector produces around 10% of the GDP of Montenegro and be one of the most dynamic economy sectors. [24] Before the global financial and economic crisis, Montenegro was characterized by increased growth which was mainly based upon high inflow of foreign direct investments. The average BDP growth rate in the period between 2006 and 2008 was 8.7%. In the period between 2006 and 2011, a growth was recorded in all economic ac-

tivities, primarily in the sectors of services and construction. Investments in construction in that period made 10% of total realized investments in Montenegro. [23] On the other hand, consequences of the economic crisis negatively influenced the construction sector. We could identify numerous problems in the legal frame in this period and as a consequence they had discontent of economic subjects in this sector, but also a fall of Montenegro on the lists of competitiveness which are published by renowned international organizations. Nowadays, the state is making various efforts to find incentive mechanisms for improving the competitiveness of this industrial branch. [02] Undoubtedly, one of the necessary assumptions for the development of this sector is stimulating regulatory framework which practically carries out the ideas of the rule of law. [01] Despite the fact that the economic crisis nega-

* University of Montenegro, Faculty of Economics, 37 Bulevar Jovana TomaÂ&#x161;evi!a , 81110 Podgorica, Montenegro; mijatj@ac.me

Mijat Jocovi - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

tively influenced the trends in the development of the construction sector, the number of economic entities in this sector hasn t reduced. For example, in 2009, in the construction sector in Montenegro there were a total of 1589 economic entities, and by the end of 2011 there were 1854 companies that carried out activities in this sector [21]. The above mentioned fact tells us about significant potential with which Montenegro deals with when it is about this economic sector. On the other hand, directly or indirectly, the construction sector influences other economic activities.[14] Also, empirical evidence has confirmed that construction sector has significant influence on GDP, labour market, national competitiveness and overall economic development.[22] After a few years of stagnation caused by the consequences of the economic crisis, construction activity in 2013 and 2014 records growth according to all indexes. Thus, total value of completed construction works during 2013, according to the data of the Statistical Office amounted to 269.7 million euros and was 9.7% higher compared to the same period in 2012. The value of new contracts on buildings was 70.4 million euros, which is 116.7% more than in the same period of the previous year, and the value of the new contracts on other construction was 65.3 million, i.e. 97.3% more compared with 2012. The strategic document of the Government of Montenegro, Directions of Economy Improvement, precisely quotes that the basic directions of the development of this sector are improved spatial planning, high quality of the construction products (sustainability), competitiveness of the construction companies and encouraging entrepreneurship, foreign investments, integration of illegal objects in the sector of formal housing, higher standards of energy efficiency and increased exploitation of energy from renewable resources. In order to achieve the above mentioned objectives, it is necessary to create a good quality legal and institutional environment. Unfortunately, general consent of the creators of the economic policy and economic entities who do the business in the construction sector in Montenegro, is there is a significant space for improving regulatory framework in this area. Research of the business environment shows that the Montenegrin economy is not satisfied with the work of state bodies in carrying out the regulatory reforms in the construction sector. For example, in the research of the Montenegro Employers Federation, Five Killers of Business , it is clearly Journal of Applied Engineering Science 14(2016)1, 352

stated that 97% of interviewed businessmen think that the current regulatory framework does not encourage companies to expand their activities.[13] The Foreign Investors Council in Montenegro has been pointing out certain flaws in the regulatory framework for years and they pay special attention to the issues which improve the development of the construction sector, primarily the problem of issuing building permits, property registration and the slowness of the state administration to service the needs of the companies who do the business in this sector. The common denominator is the fact that unstable regulatory framework in which new economic restrictions for companies have been introduced in a short period of time or increased deadlines during the application for obtaining various licenses negatively reflect on the competitiveness of the national economy. [07] Macroeconomic projections for the period 20152017 in Montenegro are significantly based upon the necessity of further development of the construction industry. According to the estimations of the creators of the economic policy in Montenegro, the period 2015-2017 will record faster growth of Montenegrin economy due to the growth of the investment activities and hiring national potentials, primarily in the construction sector. [06,07] The construction sector will experience the biggest growth under the influence of the announced investment boom and it will be around 16%, and hiring domestic construction operatives will have a multiplicative effect on those branches which are connected to the functioning of this sector: trade, transport, financial and insurance services, small production services and other.[28] The aim of this paper is to point to the significance of the regulatory changes for the development of the construction sector in Montenegro. During the topic research and writing of the paper, the authors tried to identify the deficiencies in the regulatory framework and point out their negative effect on the competitiveness of the construction sector. Also, they noticed and emphasized the positive examples where the regulatory changes in the construction sector positively influenced the development of the total competitiveness of the economy of Montenegro and an improvement of its position on the competitiveness lists which are published by the renowned international organizations. While researching the influences of the regulatory changes on the development of the construction sector, the authors used statistical and normative methods, and they also carried out 47

Mijat Jocovi - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

a range of detailed interviews with the interested parties economic entities from the construction sector, representatives from the Government and local self-management, as well as the representatives of the Employers Federation. Apart from analyzing individual legal acts, they also used publicly available publications and research of the relevant subjects in Montenegro who dealt with this topic. METHODS Key challenges in the regulatory framework of the construction sector During the analysis of the regulatory framework, it is necessary to point out the fact that the construction sector has to be regarded in the broader context as a component of the economy, thus the problems it faces in many fields are common for the total economy not enough understanding of the legislator for the businessmen, different approach in equal situations, slow procedures of obtaining licenses, insufficiently efficient judiciary system etc. [28] On the other hand, the aim of this paper is to show to concrete flaws in the legal arrangement of the construction sector. Due to the complexity of the regulations which control this area, and since there is plenty of them, because the construction sector is directly or indirectly connected with numerous business activities, the authors identified those flaws that show as the most significant in the government documents, research of the business associations and expert analyses the issue of obtaining building permits, property registration, system of public procurement. They also identified but haven t elaborated into the details other problems in this area such as flaws in the system of space planning and arrangement, communal installation of the building plots, tax environment, slowness of the administration etc. In the Strategy of developing the construction sector in Montenegro by 2020, key challenges in the regulatory framework were presented in a comprehensive way, and strategic opinion that good quality legal and institutional framework are the foundation for the development of the construction sector in Montenegro. The following issues are identified as the key problems: issuing building permits, property registration and problems with regards to the real estate registry, the question of adopting and implementing the technical standards, regulatory improvement of the system 48

for energy efficiency of the objects, efficient implementation of the system of public procurements and high-quality institutional support. [27] After doing a detailed analysis of various documents in this area, we point to the following questions as key regulatory challenges for the development of the construction sector in the future period: Creating an efficient and legally secure system for issuing building permits. Undoubtedly, the issue of building permits is in the long run the biggest challenge and so far the results in this area are described in more details further in the text. Improving overall labour law regulation in construction sector. This includes working permits regulation, work protection regulation etc. [10] Improving the quality of the arrangement of the property registration. The issue of registering and recording the property is also important for the function of the total construction sector. Some steps forward were made in this area in the previous period, but further reforms are necessary. The most significant problems of the land system in Montenegro in the previous period are the following ones: insufficiently developed land registry, frequent phenomenon of misbalance in various records in this area that is managed by state bodies state tax offices, local institutions for managing plots and constructions, state statistics, a lot of territory that is not covered with the cadastre records etc. Introducing and implementing the appropriate technical standards and European Union regulative Standardization in the construction sector became a prerequisite for running a successful business. That is why Montenegro started the procedure of introducing Eurocodes and it is necessary to bring a whole range of regulations with the obligatory implementation in the construction sector. The process of standardization is being implemented in the area of contracting, and that is why they also consider adopting FIDIC conditions of the contracts as an obligatory basis for contracting works in the system of public procurements.[18] Further improvement of the system of public procurements in the construction sector. Legislative changes since 2012 have significantly improved the total system of the public Journal of Applied Engineering Science 14(2016)1, 352

Mijat Jocovi - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

procurements in Montenegro.[09] Still, even apart from positive marks in the reform of the system of public procurements, experience in the implementation of this law, especially in the construction sector, points to certain flaws which have to be analyzed and removed so that this area can be improved. That is why we show the key drawbacks of the system of public procurements from the construction sector s point of view which influences the competitiveness of this sector, but also the total competitiveness of the national economy. These are: activities of the institutions which carry out the system of public procurements, interpreting the regulations by the entities that implement the law, disrespecting basic principles of public procurements by the offerors in practice, activities of the committees for opening and validating the offers, slowness and long duration of the procedure of public procurement etc.[20] The necessity of mutual coordination of legislature and improving the institutional capacity for realizing constructing of projects. Numerous researches of the business environment, but also official government analyses show that a particular problem for realizing investment projects in the past decades represent the slowness of the state administration and long terms for obtaining various documents and consent for building. There is also a problem of who is in charge for issuing various conditions and consents determined by not only one law, but by other regulations concerning the environment protection etc. Existing different requests which are posed for the investors, and which are not concentrated in one document, additionally makes the investors job even more difficult. On the other hand, the slowness of the administration and insufficient awareness of the significance of investments represent a special problem which needs long term attention because it can t be solved exclusively by bringing rules, but by gradual implementation of the total environment in which the state government functions. Improving the system of spatial planning. One of the most important strategic documents of the Government of Montenegro, Spatial plan of Montenegro by 2020, points to numerous problems in spatial planning whose long term high-quality solving would create assumpJournal of Applied Engineering Science 14(2016)1, 352

tions for improving the construction sector. The following problems are emphasized as the most significant ones in this document: inter-sectoral mismatch of the laws that regulate this area, not precisely defined relationships between developmental and normative content of the spatial-planned and urban planning documents, frequent and lengthy changes of municipal spatial plans and general urban plans, insufficient monitoring over the plan implementation and inefficient activities of the inspection services.[25] When The Law on Spatial Planning and building objects was brought in 2008, The laws that specially regulated certain segments were out of force. These were: The Law on Spatial Planning and Development ( Off. Gazette of Republic of Montenegro , 28/05), the Law on Plots ( Off. Gazette of Montenegro , 55/00) Law on Constructing objects ( Off. Gazette of Montenegro , 55/00, 40/08, 34/11) and the Law on Urban and Construction inspection ( Off. Gazette of Montenegro , 56/92). This law comprised four areas which used to be defined by separate laws (spatial planning and development, constructing objects, plots and inspection monitoring over the planning and constructing), which represents a rationalization for sure. One of the main objections of the investors concerns the fact that certain issues regarding building objects is treated by a range of other laws and bylaws which are partially mismatched in the parts with regards to building objects, whereas some objections were incomplete and not in compliance with the Law on spatial planning and building objects.[26, 07] We emphasize the efforts on creating a stimulating tax environment as affirmative solutions in the previous period. For example, by adopting and implementing the Law on spatial planning and building objects from 2009, a fee for using city plots was cancelled and they gave numerous benefits to the investors during the calculation of the fees for communal equipment. Also, according to the new Amendments to the Law on Property Tax which will be implemented from 01.01. 2016, one of the most significant novelty anticipates introducing exemption from paying the taxes on the objects and special parts of the residential buildings owned by the investors which are shown in the journals as investments in progress or stocks of the finished products and which are intended 49

Mijat Jocovi! - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

for further sale. Above mentioned solutions will represent a significant stimulus for further building and development of the construction sector. Evaluating the reforms in the construction sector through positions in doing business report Flanagana et. al summarize the latest developments in competitiveness in construction sector.[05] Competitiveness is a multidimensional phenomenon indispensably present at the level of firms, sectors, and the country as a whole.[16] Over the time, the concept of competitiveness has undergone significant changes.[17] Construction sector competitiveness has been a subject of interest for many years.[04] Namely, quality of construction sector is one among key elements which determinates the overall nation competitiveness.[08] The competitiveness indexes of the most prestigious international institutions (World Economic Forum, World Bank, Heritage Foundation, etc.), that empirically measure the competitiveness of the national economy, in a number of elements assess the legal and institutional aspects of construction sector. The index of easiness of doing business represents one of the most frequently used indexes concerning the evaluation of the environment of doing business of a company. High ranked index of easiness of doing business represents an important parameter for the future investors during bringing decisions on investing the capital in a country or a particular economic sector in the country. Also, the results of Doing business report are important because they talk about what the public management can do in a short period of time so that it can contribute to the easier business activities. Starting assumption of the research is

that the private sector is the bearer of the economic growth, and in order that the private sector can develop, it is necessary that administrative hurdles and limitations would be reduced to the minimum so that they can Maximize the facilitation of the interaction between economy and administration, but that there is also a legislative and judiciary system which guarantees realizing rights in practice.[11] Due to the above mentioned arguments, we thought that it is necessary to monitor the position of Montenegro in this report and to compare the improvement which has been made in the recent years concerning the areas from this report that directly affect this sector. It is necessary to point out the fact that certain problems connected with regulatory framework in the construction sector were the cause of the bad position of Montenegro on this list in previous years. These are obtaining the building permit and the issue of property registration. Officially, according to the reports for years 2014 and 2015, Montenegro has significantly reformed and improved the areas of issuing building permits and property registration. The information that the biggest 10 countries reformers in this area in 2014 tells us about the significance of reforming. Also, in 2014, the area in which most regulatory reforms were carried out is issuing building permits , and exactly 9 out of 10 countries reformers implemented the reforms.[30] Obtaining building permits is one of the key challenges for companies that do business in the construction sector in Montenegro. Based upon the report Doing Business of the World Bank from 2013, Montenegro was on a very low position 176 out of 185 countries (Table 1).

Table 1: Doing Business Report 2015

2014

2013

2012

Change compared with 2012

Starting the business

-9

Obtaining building permits

138

465

176

173

Property registration

117

108

Protecting investors

-14

Taxes

108

-10

Respecting the contract

136

135

133

-3

Closing the business

Doing Business Report

Journal of Applied Engineering Science 14(2016)1, 352

Mijat Jocovi - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

Such a bad position of Montenegro was a consequence of long, complex and insufficiently transparent and expensive procedures of obtaining building permits. Also, according to the perception of the interviewed businessmen, this area is the one which was connected with corruption. For example, the results of one research of the Montenegro Employers Federation on the quality of the business environment in Montenegro showed that 21% of the interviewees see the procedure of obtaining the building permit as an area where bribing and corruption were most expressed [12]. RESULTS AND DISCUSSION The process of obtaining building permits in Montenegro is still very complex, although significant simplifications were done and two procedures which still present a big problem to the investors are determined. These are Urban-technical conditions (45 days) and building permits (60 days). During the carrying out of the reform which aimed to facilitate the realization of the business operations and bigger inflow of the foreign capital in the reform from 2008, the following procedures were terminated: solution on location, solution on appointing the performer of the Main project revision, solution on approving preparation works, solution on urban consent. Since the reforms that were carried out in 2009 showed as very effective and beneficial, the following reforms were terminated in 2010: approval for carrying out geological researches (for all objects), consent to the elaborate on geological research, consent on electric power, sanitary consent, and agricultural consent. In the Doing Business report for 2013 they recognized the efforts of the Government of Montenegro to reduce time, financial and procedural overload of the investors during issuing building permits. Although this area experienced significant reforms, it is still necessary to point out that the efforts were not good enough for improving the position primarily due to the fact that collecting documentation and total procedure was carried out by investors themselves. Apart from that, although the law defined and simplified the regulations, according to the report - it is stated that this procedure still lasts for too long in practice. Still, in Doing Business report from 2014 in the area of issuing building permits, a step forward was made for 11 places (see the Table 1). The biggest novelty in this area is introducing the principle of one window (one stop shop) where one can obtain all necessary consents for the perJournal of Applied Engineering Science 14(2016)1, 352

mit at one place. Significantly improved position in this criterion is a result of reduced number of procedures for obtaining the permit from 16 to 9, as well as reduced terms of delivery which shortens the procedure from 267 to 158 days compared with the Report for the year 2013. On the other hand and, with regards to costs, Montenegro was still on the top with the biggest costs which amount more than 60,000 Euros on the Doing Business model. The biggest amounts in costs are high fees for communal equipment of the plot, which amount around 45,000 Euros in this case on the example of the Capital City Podgorica which was comprised by the Report. Still, in the Doing Business report for 2015, the position has improved a lot because it recorded reduced duration of the procedure, but the lower costs paid by the investor as well.[19] Viewed for the period 2012-2015, Montenegro improved its position 35 places with regards to the criterion of issuing building permits. In the area of property registration, an improvement of 21 places in the period 2012-2015 was recorded, primarily due to simplified property registration by introducing a notary system. Better position is a result of reduced number of procedures for obtaining the solution on real estate registration in the cadastre from 7 to 6 days, while the terms and costs remained the same. According to the data of the index of easiness of doing business for the year 2013, Montenegro took the 51st place, which represents a fall of four places compared with the previous year.[29] In the report for 2014 year, it took the 44th place, which represents a big step forward on the ranking list.[30] Finally, in the Report for the year 2015, Montenegro significantly improved its position and took the 36th place.[31] The biggest changes which led to improving the position on the ranking list derive from the reforms on areas of obtaining building permits and property registration.[03, 15] CONCLUSION The construction sector as an economic activity is directly or indirectly connected with a big number of regulations of various legal power and content. Out of total number of real estate and its registration, spatial planning, issuing building permits, tax environment, over the carrying out of the contract on economic-legal activities, the common denominator of the regulative is the need that it should be predictable, mutually adjusted and applicable on the business entities that it refers to. 51

Mijat Jocovi - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

The research of the influences of the regulatory changes on the development of the construction sector imposes itself as one of the basic conclusions that the efficient transformation of regulation, primarily in the area of building objects and property legal relations is a precondition for improving this sector. Also, the whole legal system which affirms the idea of the rule of law is a necessary prerequisite for developing the construction sector. We noticed and clearly pointed out certain problems in the legal framework which we consider they negatively influenced the improvement of the competitiveness of this sector and the national economy. As the most significant, the following ones are identified: trend of provisions instability, existence of mutual collision of laws and sublegal acts, regulation of spatial planning, registering property and system of public procurement. We particularly pointed out the fact that frequent absences of applying the adopted rules, the slowness of the administration and lack of awareness on the significance of investment, represent a long term problem which cannot be solved by bringing provisions, but by transforming total state management into the public service of citizens and economy. Finally, a common conclusion is imposed that the results up till now, especially reforms that were carried out after the economic crisis in the construction sector show that Montenegro seriously approaches this issue, and the best evidence for this attitude is the improving the position of Montenegro on the competitiveness lists of relevant international organizations. REFERENCES 1) Bevan, A., Estrin, S. and Mayer, K. (2003). Foreign investment location and institutional development in transition economies, International Business Review 13, pp. 43-64. Available at: http://www.klausmeyer.co.uk/publications/2004_bevan_meyer_estrin_IBR.pdf. 2) !etkovi" J. et. al. Primary directions and advancements in competitiveness of Montenegrin construction sector , Procedia Engineering, ISSN: 1877-7058, Vol. 117, 2015., pp. 780-790. 3) !etkovi", J., Kne evi", M., arkovi", M., Murgul, V., Vatin, N. (2014), Development and competitiveness improvement of the construction sector in Montenegro Applied Mechanics and Materials, Vols. 638-640, pp. 2465-2470. 52

4) Dangerfield B., Green S., Austin S., (2010) Understanding construction competitiveness: the contribution of system dynamics, Construction Innovation, Vol. 10 Issue: 4, pp.408 420. 5) Flanagana R., Lua W., Shenb L., Jewella C., (2007), Competitiveness in construction: a critical review of research, Construction Management and Economics, Volume 25, Issue 9, pp. 989-1000. 6) Foreign Investors Council in Montenegro. (2013). White pages 2013: view ahead, pp. 15. Retrieved from website: www.mfic.me/ files/BijelaKnjiga.pdf. 7) Foreign Investors Council in Montenegro. (2013). White pages 2013: view ahead, pp. 46-47. Retrieved from website: www.mfic. me/files/BijelaKnjiga.pdf. 8) Huggins R., Izushi H., (2015), The Competitive Advantage of Nations: origins and journey, Competitiveness Review, Vol. 25 Issue: 5, pp.458 470. 9) Jocovic M., (2013), Current problems in implementation of the Law on public procurements in Montenegro, Law and economy journal for legal-economic theory and practice, no. 7-9, pp. 514 - 525. 10) Lawrencea R., Paredes Gilb M., Flückigerc Y., Lambertb C., Wernad E., (2008) Promoting decent work in the construction sector: the role of local authorities, Habitat International, Volume 32, Issue 2, pp. 160 171. 11) Milovic N., (2012), Common market and policy of competitiveness of the European Union, The University of Montenegro The Faculty of Economics, pp. 210-211. 12) Montenegro Employers Federation, Creating the environment for sustainable development of companies in Montenegro, pp. 21. 13) Montenegro Employers Federation. (2012). Five killers of business, pp. 5-6. Retrieved from: www.poslodavci.org. 14) Polenske K., Sivitanides P. (1990), Linkages in the Construction Sector, The Annals of Regional Science, 24 (2): 147-161. 15) Popovi", S., Djurovic, N., Murgul, V. (2015), Formation, Development and Issues of Montenegro Rural Settlements in the Case of Village Orja Luka in Bjelopavlici Procedia Engineering, Vol. 117, pp. 832-840. Journal of Applied Engineering Science 14(2016)1, 352

Mijat Jocovi! - Role of regulatory reforms for development and quality improvement of the construction sector in Montenegro

16) Porter , M. (1990), The competitive advantage of nations , New York: Free Press. 17) Porter, M., Delgado, M., Ketels, K., Stern, S. (2012), The determinants of national competitiveness , National Bureau for Economic Development, NBER Working Paper No. 18249. 18) Rute i! S., et. al., (2015), Analysis of the Situation in Montenegrin Civil Engineering Sector from the Point of Application of National Regulations and the EU Technical Standards in Construction, Procedia Engineering, ISSN: 1877-7058, Vol. 117, pp. 905 - 915. 19) See for more details: http://www.doingbusiness.org/data/exploreeconomies/ montenegro#dealing-with-construction-permits. 20) See for more details: Melovic B., Jocovic M., (2013), Public procurement as a determinant of competitiveness of the construction sector in Montenegro , Nehnutelnosti a bývanie, Slovak University of Tehnology in Bratislava, 5, ISSN: 1336-944X, pp. 94-101. 21) Statistical Office of Montenegro, Statistical Yearbook 2011, Podgorica, 2011, pp. 137-146. 22) Tan W., Construction and Economic Development in Selected LDCs: Past, Present and Future. Construction Management and Economics, 20(7), pp. 593-99. 23) The Government of Montenegro Agency for promoting foreign investments, Strategy of attracting foreign direct investments 2013-15, Podgorica 2013, pp. 15-22. Available at: www.gov.me/.../FileDownload. aspx?rId=126665...2.

Journal of Applied Engineering Science 14(2016)1, 352

24) The Government of Montenegro, Directions of the economy development 20132016, Podgorica 2013, pp. 60-61. Available at: www.gov.me/.../FileDownload. aspx?rId=127804...2. 25) The Government of Montenegro, Spatial planning in Montenegro by 2020, (2008), Podgorica, pp. 28-29. Available at: http:// www.gov.me/files/1234791491.pdf. 26) The Government of Montenegro, Strategy of developing the construction sector in Montenegro by 2020, (2010), Podgorica, pp. 26-27. Available at: www.gov.me/files/1260782780.pdf. 27) The Government of Montenegro, Strategy of developing the construction sector in Montenegro by 2020, Podgorica, 2010, pp. 20-29. Available at: www.gov.me/files/1260782780. pdf. 28) Vasiljevic, M. (2011). Economy and rule of law Law and economy journal for legal-economic theory and practice, 4 (6), pp. 17-43. 29) World Bank, Doing business 2013 Smarter regulation for Small and Medium sized Enterprises. Available at: http://www.doingbusiness.org. 30) World Bank, Doing Business 2014 - Understanding Regulations for Small and MediumSize Enterprises. available at: http://www. doingbusiness.org. 31) World Bank, Doing Business 2015 - Going Beyond Efficiency, available at: http://www. doingbusiness.org. Paper sent to revision: 23.12.2015. Paper ready for publication: 03.03.2016.

Original Scientific Paper

doi:10.5937/jaes14-9842

Paper number: 14(2016)1, 353, 54 - 60

ON THE IMPORTANCE OF MANAGERIAL AND ORGANISATIONAL VARIABLES IN THE QUANTITATIVE RISK ASSESSMENT Maria Francesca Milazzo* University of Messina, Messina, Italy Common practises for Quantitative Risk Assessment (QRA) include the estimation of frequencies of releases and related initial causes; these are a function of several parameters such as components failure rates, probabilities of human error, equipment damage and managerial factors. The availability of general values for such parameters from the literature simplifies the work of the risk analyst, but standardised results are provided, which unfortunately do not permit taking into consideration the plantÂ&#x2019;s specificity. The specificity of the establishment is defined through its management system, thus if managerial and organisational factors are neglected or not proper assessed, risk analysis for two identical establishments, characterised by totally different management systems, gives the same results and this appears absolutely unacceptable especially when risk analysis is used for risk-based decisions. This paper aims quantifying the effects of managerial and organisational variables on the frequency of losses of containment of pipeworks, by using a simple and flexible method developed by Milazzo and co-authors in 2010. Such a methodology has been tested on a new case-study and the results of the assessment have been evaluated from both the sensitivity and uncertainty points of view. An application has been shown with respect to the alkylation unit of a refinery. Key words: Industrial safety, Quantitative Risk Assessment, Loss of containment, Cause of failure, Pipework, Frequency. INTRODUCTION Several factors, including human elements, hardware or technical elements and the environment/climate where workers operates, contribute to safety in major hazard plants [24,7], such factors act through a complex interaction. In this frame, organisational and managerial aspects affect the human behaviour; this finally has an effect on the system performances. By analysing the mechanism of interaction, it can be evidenced that the role of management is central to the safe functioning of plants, in particular in chemical industry, where some reactions are not always easy to be managed or controlled. Due to the loss of control of chemical process, incidental scenarios, such as fires explosions and toxic dispersions, could occur. Davoudian et al. [02] suggested assessing the effects of managerial and organisational variables on safety by modelling the system (plant) as a whole and, then, quantifying and incorporating managerial and organisation impacts into Quantitative Risk Assessment (QRA). After this study,

several interesting approaches were suggested to describe the formal organisation of processes and the numerous previously mentioned interactions at different levels. A detailed overview on these approaches was given by Nivolianitou and Papazoglou [17], this review was more recently updated by Milazzo et al. [12]. The literature shows that approaches for the quantitative assessment of managerial and organisational impacts mainly derive from the nuclear field [9-15]. The modelling of such impacts is essential, mainly because Quantitative Risk Analysis (QRA) provides useful information to support decisions, which are obviously based on an economical appraisal applied to several solutions [1]. The most relevant methods for the quantification of management-related safety problems in chemical industry are the MACHINE (Model of Accident Causation using Hierarchical Influence Network) [4], the Integrated Safety Method ISM [14], the Work Process Analysis Model WPAM [2,3], the System Action Management approach SAM [22], the Omega Factor Method [16], the I-Risk (Integrated Risk) approach [20-21], the

* University of Messina - Dipartimento di Ingegneria Contrada di Dio, 98166, Messina, Italy; mfmilazzo@unime.it

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

Organisational Risk Influence method ORIM [18] and, finally, the ARAMIS methodology [23]. This work aims testing a simple and flexible method for the quantification of the effects of managerial and organisational factors on the frequency of loss of containment of pipeworks, which was suggested by Milazzo et al. in 2010 [12]. The data (percentage of the causes of failure), needed for the assessment of such factor, have been updated with respect to those used by Milazzo et al. An application allowed testing the method, it relates to a new case-study from the chemical industry, i.e. a refinery. Then both the sensitivity and the uncertainty of the results have been assessed by using the qualitative approach suggested in Milazzo and Aven [11]. The structure of the paper is the following: in the first section, the approach of Milazzo et al. is briefly described; the second section gives the application to the case-study; in the third section, results are discussed and commented in terms of sensitivity and the uncertainty. METHODOLOGY The approach suggested by Milazzo et al. [12] for the quantification of the frequencies of loss of containment (or random rupture) in pipeworks is based on two steps: I. (i) the definition of the relationship between the measures of prevention of incidents, adopted by the Company, and the causes of failure leading to the loss of containment; II. (ii) the estimation of the weight coefficients for the causes of failure, to be used for the modification of the frequencies by including the effects of managerial and organisational factors. III. Subsequently, the frequencies of breakage/ rupture, obtained from the literature and commonly used in QRA, are modified according to the equation proposed by Papazoglou et al. in 1999 [18]. Thus the method of Milazzo et al. consists of an examination of the whole plant (as suggested by Davoudian et al. [02]), to define how the measures of risk prevention adopted inside the establishment can influence the frequency of rupture. This is made by auditing each unit of the establishment, in order to allow identifying the causes of failure which can occur and the measures which can prevent them. The weight coefficients for the causes of failure, which are used to apply the method, are the percentages Journal of Applied Engineering Science 14(2016)1, 353

of failures and relate to each unit of the establishment. Papazoglou et al. [18] analysed data of incidents in chemical industry and showed that the frequencies of release from various equipment spans two orders of magnitude and has certain symmetry around the average values. Thus, the frequencies of failure can be modified by using the following equation, whose application needs the weight coefficients ai (percentage of the cause of failure i): where: fmod = modified frequency of failure (frequency of the loss of containment); fav = average frequency of failure based on world-wide experience (average frequency of the loss of containment); ai = weight coefficient for audit area i (percentage of the causes of failure in the audit area i); xi = parameter indicating the judgement of the effectiveness of the prevention measure related to the cause of failure i. The parameter xi assumes the following values: - 1 if the plant is judged GOOD; 0 if the plant is judged AVERAGE; + 1 if the plant is judged POOR. The use of the same statistical data for each installation under analysis does not permit to take into account plant-specific information. Different installations may differ from the point of view of the percentage of causes of failure, thus it is necessary to correct the weight coefficients taken into account their specificity [12]. To achieve this scope, the approach of Milazzo et al. firstly excludes the causes of failure that can be prevented through the adoption of appropriate prevention measures, then, applies the mathematical model represented by equation (1) and uses installationspecific information to support the calculation of the percentage of the causes of failure. APPLICATION To test the approach previously described, a case-study was chosen, it is a refinery (confidential). As an example, in this paper, only the alkylation unit is described. Alkylation unit The alkylation process produces gasoline with a high octane number, starting from the gaseous byproducts of other units, especially from the cracking and reforming. These by-products are generally constituted by mixtures of iso-butane and olefins having 3-5 atoms of carbon. Acid catalysts are employed to achieve acceptable reaction rates 55

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

without reaching high temperatures. Due to the acid environment, this unit is considered the most critical of a refinery from the point of view of the prevention and management of random ruptures. Failure causes and preventive measures The application of the method of Milazzo et al. aims estimating the influence of prevention measures on fav, which were a priori judged GOOD (xi = - 1). Thus the problem is to determine which causes of failure can be prevented by the measures adopted by the Company. An audit was made to identify causes of failure, preventive

measures and related effectiveness. Table 1 gives all the relevant causes of failure and their percentage. This data was extracted from a European database of DVN (Det Norske Veritas) [6] and was used for the elaborations of the present work. The weight coefficients of Table 1 needed to be corrected to account for the evidence that modern design and manufacture might reduce the number of failures due to certain causes. The way to correct the weight coefficients was defined in agreement with the plant management of the establishment.

Table 1: Percentage of causes of failure [06] Failure cause

Corrosion

Erosion

External pressure

Temperature

Wrong installation

Partial cause

[%]

Wrong material

1.68

Corrosive contamination

0.38

Exceptional conditions

1.01

Aggressive environment

1.03

Poor protection

0.74

Zinc embrittlement

0.06

Cooling water circuit

0.06

Galvanic corrosion

0.33

Unknown

4.11

Turbulent flow

0.01

Unfavourable flow path

0.22

High flow speed

0.14

Erosive external environment

0.05

Unknown

0.27

Erosive contents

0.11

Removed pipe supports

0.28

Failure of pipe supports

0.98

Poor design of supports

1.14

Unknown

0.11

External pressure

0.48

Insufficient material specification

0.87

Thermal pressures

0.38

Change of contents

0.60

Thermal shock

0.38

Poor pipe specification

0.02

Domino effect

0.54

Unknown

1.01

Wrong partsÂ&#x2019; placement

0.16

Installation error

2.64

Insufficient equipment

1.09

Unknown

0.11

Journal of Applied Engineering Science 14(2016)1, 353

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

Table 1: Percentage of causes of failure [06]. Failure cause

Procedural error

Impact

Partial cause

[%]

Pipe not cleaned before opening

4.38

Wrong pipe worked on

0.87

Wrong equipment status

3.62

Wrong operationsÂ&#x2019; order

2.90

Wrong (dis)connection

0.76

Pipe insufficient insulated

1.56

Equipment not brought back to normal status

0.33

Unknown

3.78

Impact of a nearby installation

1.68

Human impact

0.85

Falling object as a result of a natural cause

0.22

Vehicle impact

1.57

Unknown

0.43

Total

100

The measures, adopted by the Company to prevent failures (such as corrosion, erosion, pipe defect and other structural damages) are radiographic testing, ultrasonic testing, liquid penetrant testing, magnetic particles testing and visual inspections. Information on equipmentÂ&#x2019;s past life is stored in a database managed by a specific software developed by the Company, this was essential to identify and assess the causes of failure occurring in each pipework. The corrosion phenomenon was analysed in detail. Data of Lees [10] allowed distributing the corrosion causes of Table 1 amongst several sub-causes as given in [12]. A detailed analysis of the fluid flowing in the piping and the process conditions were necessary to define which sub-causes occurs. Secondary causes, which were considered not credible, were excluded and the percentage of failures due to the corrosion was corrected. Then, in order to estimate the effect of measures of risk prevention on fav, through equation (1), a judgment xi for each adopted measure has been formulated. Each one was defined in terms of efficiency in

identifying a given failure causes. Average frequencies To show how the approach works, only one incidental hypothesis is described. The event is a breakage of a pipe coming from the alkylation reactor, three dimensions of leakage were considered (see Table 2). The average frequencies (fav) are those given in the Safety Report (the document refers to the data from HSE [8]). After the a priori exclusion of some causes of failure, the modification of the mean frequency (fav) obtained from the literature was needed. This value was reduced by a percentage equal to the excluded causes of failure. Thus equation (1) was applied to the a priori modified frequency. RESULTS The frequencies of loss of containment modified by the application of the method are shown in Table 3. Several examined case-studies showed that the frequencies of random events generally decrease from 1 to 2 orders of magnitude.

Table 2: Leakage cases and frequencies.

Table 3: Leakage cases and frequencies.

Event

fav [event/y*m]

Event

fav [event/y*m]

Rn1a

Hole size 3 mm diameter

1 10-5

Rn1a

Hole size 3 mm diameter

9.75 10-7

Rn1b

Hole size 25 mm diameter

5 10-6

Rn1b

Hole size 25 mm diameter

4.87 10-7

Rn1c

Guillotine rupture

1 10-6

Rn1c

Guillotine rupture

9.75 10-8

Journal of Applied Engineering Science 14(2016)1, 353

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

The entity of the risk reduction is visualised in Figure 1 by using a risk matrix, where the x and y axes respectively give the consequence and the frequency of the events. The following four classes of consequence are defined based on the effects thresholds: D high percentage (50 %) of fatalities, C low percentage of fatalities (1 %), B irreversible effects and A reversible effects (see details in [25]). Three levels of risk are defined for the risk-based decisions,

Figure 1: Risk matrix

i.e. the acceptability level, the ALARP (As Low As Reasonable Possible) level and the unacceptability level. In Figure 1, these levels respectively correspond to the white, the grey and the red zone. The results of Figure 1 allow verifying the reduction of the risk level by mean of the adoption of

certain preventive risk measures. The aim of the Company is bring the event from the ALARP zone to the acceptability ones. DISCUSSION Given that some steps of the assessment include subjective judgments by the risk analysts, it is important to know how to make the risk assessment as less as possible affected by subjectivity. A subjective evaluation implies that different analysts may provide different assessment for the weight coefficients (ai) and, also, different judgments for the risk prevention measures (xi). A sensitivity analysis showed the parameter which is the most significant for the final evaluation [16]. The variables with the highest influence on the fmod are the average frequency fav and the weight coefficients ai. This conclusion is not sufficient to consider at what extent the modelling corresponds to the reality and where implementations are needed, indeed the risk analyst has to comment about its results also based on the uncertainty associated with the assumptions made in modelling to simplify the process. To this purpose, in this paper the sensitivity and the uncertainty were evaluated, as suggested by Milazzo and Aven [11]. This method allows the assessment and categorisation of the assumptions (so-called uncertainty factors) with respect to both the uncertainty and the sensitivity scores (U and S) proposed by Flage & Aven [05] and given in Table 4.

Table 4: Uncertainty and the sensitivity scores [05] Aspect

Score

Interpretation

Low (L)

One or more conditions: The assumptions made are seen as very reasonable. Much reliable data are available. There is broad agreement/ consensus among experts. Phenomena involved are well understood; the models used are known to give predictions with the required accuracy.

Medium (M)

Conditions between those characterizing low and high uncertainty.

High (H)

One or more conditions: The assumptions made represent strong simplifications. Data are not available, or are unreliable. There is lack of agreement/ consensus among experts. Phenomena involved are not well understood; models are non-existent or known/ believed to give poor predictions.

Low (L)

Unrealistically large changes in base case values needed to bring about altered conclusions.

Medium (M)

Relatively large changes in base case values needed to bring about altered conclusions.

High (H)

Relatively small changes in base case values needed to bring about altered conclusions.

Journal of Applied Engineering Science 14(2016)1, 353

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

Table 5 gives the results of the uncertainty and the sensitivity assessment; uncertainty factors were determined for each steps of the proposed approach of Section 2. The first assumption is the common use of representative classes of fluids to describe all fluid characteristics. Substances, characterised by the same hazard, are usually grouped to reduce the number of cases of release, this determines low degrees of uncertainty and sensitivity. Table 5: Uncertainty and sensitivity scores Uncertainty factors (Assumptions)

Representative fluid are able to describe all fluids characteristics

Average frequencies and failure causes are based on literature data.

Efficiency of the inspection techniques

Only one failure occurs during a certain interval of time

The failure is quickly detected

Company and industry requirements are followed

Pipeworks are tested and inspected before and during the installation

The greatest difficulty in assigning frequencies of breakage and percentage of failures is due to the lack of appropriate data (second assumption). Uncertainties are due to the adoption of data derived from other context. This assumption leads to high degrees of uncertainty and sensitivity (see also [13]). The third factor is the assumption that only one failure event or failure mode occurs during a certain interval of time and the forth ones that failures are immediately detected when they occur. It is well known that this is not absolutely true. The fifth and sixth uncertainty factors address respectively the assumptions that the installed pipeworks are adequately tested and inspected prior to the process start up and that the process is within the design criteria and requirements/recommendations. Also the truthful of these assumptions is questionable. The sensitivity and the uncertainty scores showed that the use of average frequency and failure causes from the literature is the factor mostly affecting the assessment. Thus the analyst must be care in selecting such data.

Journal of Applied Engineering Science 14(2016)1, 353

CONCLUSION Given that the main cause of accidents in pipeworks are often due to deficiencies in the corporate structure, many techniques have recently been developed and allow estimating the effects of managerial and organisational factors in the risk assessment. Common practises conservatively include the influence of measure of risk prevention and mitigation, whereas this work has permitted to apply a simple and flexible approach for the calculation of loss of containment frequencies taking into account managerial and organisational variables. Results showed that the frequencies of random events generally decrease by about an order of magnitude or more in some cases. Moreover, given that the proposed method is affected by several subjective judgements, it was possible to comment on how to make the assessment as less as possible affected by subjectivity. The sensitivity and the uncertainty were evaluated and the results showed that the use of generic frequency and failure causes from the literature is the factor mostly affecting the assessment. Thus their selection must point to more reliable data. REFERENCES 1) Abrahamsen, E. B.,Asche, F., Milazzo, M.F. (2013) An evaluation of the effects on safety of using safety standards in major hazard industries. Safety Science, 59: 173-178. 2) Davoudian, K., Wu, J. S., Apostolakis, G., (1994) Incorporating organizational factors into risk assessment through the analysis of work processes, Reliability Engineering and System Safety, 45, 85-105. 3) Davoudian, K., Wu, J. S., Apostolakis, G. E., (1994) The work process analysis (WPAM II), Reliability Engineering and System Safety, 45(1-2), 107-125. 4) Embrey, D. E., (1992) Incorporating management and organization factors into probabilistic safety assessment, Reliability Engineering and System Safety, 38(1-2), 199-208. 5) Flage, R., Aven, T., (2009) Expressing and communicating uncertainty in relation to quantitative risk analysis (QRA), Reliability & Risk Analysis: Theory & Applications, 2(13), 9Â&#x2013;18. 6) Flemish Government, LNE Department Environment, Nature and Energy Policy Unit Safety Reporting Division (2009), Hando59

Maria Francesca Milazzo - On the importance of managerial and organisational variables in the quantitative risk assessment

book of failure frequencies (Appendix). 7) Gordon, R. P. E., (1998) The contribution of human factors to accidents in the offshore oil industry, Reliability Engineering and System Safety, 61, 95-108. 8) Healthy & Safety Executive, (2012) Failure Rate and Event Data for use within Risk Assessments. Report available at: http://www.hse.gov. uk/ (accessed on the 1st December 2015). 9) Izquiedo-Rocha, J. M., Sanchez-Perea M., (1994) Application of integrated safety assessment methodology to emergencies procedures of SGTR of a PWR, Reliability Engineering and System Safety, 45(1-2), 159-173. 10) Lees, F. P., (1996) Loss Prevention in the Process Industries, Elsevier, London. 11) Milazzo, M. F., Aven, T., (2012) An extended risk assessment approach for chemical plants applied to a study related to pipe ruptures, Reliability Engineering and System Safety, 99, 183-192. 12) Milazzo, M. F., Maschio, G., Uguccioni, G., (2010) The influence of risk prevention measures on the frequency of failure of piping, International Journal of Performability Engineering, 6(1), 19-33. 13) Milazzo, M. F., Vianello, C, Maschio, G., (2015) Uncertainties in QRA: Analysis of losses of containment from piping and implications on risk prevention and mitigation, Journal of Loss Prevention in the Process Industry, 36, 98-107. 14) Modarres, M., Mosleh, A., Wreathall, J. A., (1992) Framework for assessing influence of organization on plant safety, Reliability Engineering and System Safety, 38(1-2), 157-171. 15) Montmayeul, R., Monsneron-Dupin, F., Llory, M., (1994) The managerial dilemma between the prescribed task and the real activity of operator: some trends for research on human factors, Reliability Engineering and System Safety, 45(1-2), 67-73. 16) Mosleh, A., Goldfeiz, E. B., (1995) An Approach for Assessment the Impact of Organizational Factors on Risk. Report no. UMNE-95-003, University of Maryland. 17) Nivolianitou, Z. S., Papazoglou, I. A., (1998) An auditing methodology for safety management of the Greek process industry, Reliability Engineering and System Safety, 60, 185-197. 60

18) Øien, K., (2001) A framework for the establishment of organizational risk indicators, Reliability Engineering and System Safety, 74(2), 147-167. 19) Papazoglou, I. A., Aneziris, O., (1999) On the quantification of the effects of organizational and management factors in chemical, Reliability Engineering and System Safety, 15(1): 545-554. 20) Papazoglou, I. A., Aneziris, O., Post, J. G., Ale, B. J. N., (2002) Technical modeling in integrated risk assessment of chemical installations, Journal of Loss Prevention in the Process Industry, 15(6), 545-554. 21) Papazoglou, I. A., Bellamy, L. J., Hale, A. R., Aneziris, O., Post, J. G., Oh, J. I. H., (2003) IRisk: development of an integrated technical and management risk methodology for chemical installations,. Journal of Loss Prevention in the Process Industry, 16(6), 575-591. 22) Patè-Cornell, E. M., Murphy, D. M., (1996), Human and management factors in probabilistic risk analysis: the SAM approach and observations from recent applications, Reliability Engineering and System Safety, 53(2), 115-126. 23) Salvi, O., Debray, B., (2005) A global view on ARAMIS, a risk assessment methodology for industries in the framework of the SEVESO II directive, Journal of Hazardous Materials, 130(3), 187-199. 24) Schönbeck, M., Rausand, M., Rouvroye, J., (2010) Human and organisational factors in the operational phase of safety instrumented systems: A new approach, Safety Science, 48(3), 310-318. 25) Vianello C., Guerrini L., Maschio G., Mura A. (2014). Consequence analysis: comparison of methodologies under API standard and commercial software. Chemical Engineering Transactions, 36, 511-516. Paper sent to revision: 24.12.2015. Paper ready for publication: 02.02.2016.

Journal of Applied Engineering Science 14(2016)1, 353

Original Scientific Paper

Paper number: 14(2016)1, 354, 61 - 67

doi:10.5937/jaes14-9932

DEVELOPMENT OF CLUSTER APPROACH IN TOURISM (RUSSIA CASE STUDY) Vera Rukomoinikova* Volga State University of Technology, Yoshkar-Ola, Russia Ann Polukhina Volga State University of Technology, Yoshkar-Ola, Russia The concept of tourism clustering is currently in the focus of tourism development on national and regional levels. The research is based on international academic literature review and the analysis of Russian experience. The paper analyses the dynamics of the tourism poten-tial of the partner regions joined into the cluster Velikaya Volga (The Big Volga), based on the expert opinion. There is a cost-benefit analysis of the tourism industry in the regions included into the tourism cluster using statistical data. The analysis-based diagrams show the differentiation of the Volga regions in terms of tourism potential use. Econometric approach allowed studying the dependence of tour-ism potential indicators on the tourism cluster Velikaya Volga revenue. The results of the research allow grouping the regions included in the cluster depending on the efficiency of their tourism potential implementation. The research also shows the significance of the com-parative evaluation of tourism cluster potential. The comparative method used for the cluster analysis allows enhancing the development of the regional tourism. Key words: Cluster, Tourism development strategy, Tourism sector, Regional economy INTRODUCTION Tourism in the 20th century has become a unique phe-nomenon and an integral part of life of hundreds of mil-lions of people. This marketable economic activity is one of the most popular among entrepreneurs. According to the esti-mates of the World Tourism Organization (UNWTO), the total annual revenue from the tourism industry will have reached 2 USD trillion by 2020 [04]. Other data suggest that tourism revenues long ago made up about 4 USD trillion [01]. The share of tourism industry in the Gross Domestic product of the Russian Federation is 2.5% including Tourism Multiplier Effect 6.3%. Provided that there is an effective support from the state and a proper promo-tion of tourism opportunities the tourism share in the GDP of the RF may significantly increase. At the same time in the Travel and Tourism Competitiveness Index published as a result of the World Economic Forum in March 2015, Russia was ranked 45th out of 141 coun-tries, although the natural resources of our country are rated 34th and the objects of cultural heritage 21th [08].

In order to effectively use the tourism and recreation capacity the Russian Federation adopted the Federal Target programme in 2011 Development of domestic and incoming tourism in the Russian Federation for 2011-2018 with the special focus on creation and de-velopment of regional tourism clusters. The document states: Cluster approach assumes geographic concentrations of enterprises and firms involved in production, promotion and sale of a tourist product and performing other activities within the same of adjacent tourism or recreational industry. Within the framework of establish-ing tourism and recreational research-based clusters, including the ones initiated by the state and private partnerships, the necessary and sufficient conditions for the fast development of tourism infrastructure and re-lated services will be created. Positive practices, obtained as a result of several pilot tourism and recreational clus-ters, are subject to implementation on the national level in the regions for the development of domestic and incoming tourism, thus, fostering rapid return of state and private investments [08].

* Volga State University of Technology, Yoshkar-Ola, Russian Federation; PoluhinaAN@volgatech.net

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

BACKGROUND It is necessary to consider the concept of a cluster. There are a lot of definitions of a cluster in literature and wide experience of the development of cluster economics in many countries of the world. According to M. Porter, who is considered to be the initiator of the cluster theory, a cluster is a geographical proximate group of interconnected companies (suppliers, manufacturers, etc.) and associated institutions (educational institutions, state management authorities, infrastructure companies) in a particular field, linked by commonalities and externali-ties [10]. M. Porter emphasizes that successful cluster progress requires application of sustainable development strate-gy. In his opinion, clusters represent a kind of new spa-tial organizational form of effort consolidation of dif-ferent stakeholders, meant to achieve the competitive advantage in economics. The aim of cluster policy is to create prospective opportunities for the development of the business and the region. Thus, every cluster contrib-utes to the long-term business development strategy for the period of 5-10 years [09]. As it is commonly known, Michael Porter suggested ap-plying the cluster theory in industry, however nowadays this theory is actively developed in terms of strategies for the regional tourism development. Tourism cluster is generated around so called core business, the business of tourist firms, creating a tourist product. These firms repurchase the services of other businesses: hotel and catering, transfer, sales, entertainment, etc. Companies involved in business operations crease a tourism cluster. The key principle of the cluster ad-vantage: cooperation on the regional level allows to compete on the global level. Clustering may be initiated by both state and businesses. The efforts of the state are usually aimed at creating favourable conditions for the cluster development and promotion of relations in-side the cluster, rather than supporting separate busi-nesses or industries. Tourist companies have to operate under competition on the domestic and external mar-kets. It fosters cluster formation. It is common knowledge, that tourism industry uses associations as a form of cooperation, which is a prototype of a cluster [03]. According to A. Aleksandrova s research of internation-al tourism, cluster development in tourism 62

proved its efficiency [02]. The necessity to establish technological linkages (mainly business linkages) between enterprises and sectors of economy, involved in manufacturing and sale of the tourist product, is one of the characteristic features of tourism cluster evolvement. In other words, by these linkages we mean creating conditions for un-locking the tourism and recreational potential of the region. Tourism clusters are formed based on the key tourism and recreational resources of the region. In addi-tion to enterprises and organizations, directly involved in production and delivery of tourist products and services, a tourism cluster can include representatives of the au-thorities, research institutions, educational institutions, professional associations, representatives of the com-munities, etc. to act as the participants of the tourism cluster. A tourism cluster may be established on the local (municipal) level, as well as on the regional level. Re-searchers note that cluster approach in tourism signifi-cantly contributes to the economic growth of the region [14]. In the field of tourism there are models, which are developed mainly for the enhancement of cluster com-petitiveness [12]. Innovative cluster models, including a lot of interlinked cooperation-based sectors have recently come into the focus of researchers attention [06, 15]. Some examples of interregional tourism clusters can also be found in literature[07]. Nowadays the cluster-based approach to the regional development is better understood in Russia [13]. Organi-zational and conceptual principles of cluster formation are provided in the Concept of cluster policy in the Rus-sian Federation, adopted by the government of the Rus-sian Federation in 2008. The development of tourist clusters in the region goes through several stages: from the idea, initiated by the local authorities or business representatives to the de-termination of the spatial strategic development, i.e. development of the complex programme of tourism development in the region. N. Shabalina describes the following opportunities that appear in the region due to cluster approach in tourism: 1. the interests of all active participants of the tourism cluster are taken into account; 2. sustainable social and economic development of the area; Journal of Applied Engineering Science 14(2016)1, 354

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

3. increase in the number of taxpayers and tax base; 4. a tool for interaction with the business community; 5. grounds for the diversification of spatial develop-ment; 6. promotion of the economic boost in the region; 7. intensification of initiatives aimed at stimulating the private sector of economy through the programmes of training and retraining of personnel); 8. creating infrastructure for R&D; 9. cost reduction as a result of economy of scale, due to close cooperation between the manufacturers and con-sumers; 10. opportunities for more successful entry to the global market; 11. stimulating the increase in labour productivity and implementation of innovation; 12. for small and medium-size business the access to financial resources is facilitated; 13. effective promotion of regional initiatives onto the federal level; 14. strengthening cooperation between business representatives and research groups in finding solution for the problem tasks.

Simultaneously N.Shabalina defines the key issues of formation and development of tourism clusters: Deficiency of professional tourism staff, capable of understanding all the advantages and benefits of this form of cooperation; Reluctant attitude of authorities to innovations; Lack of strategic planning tourism practice based on state and private partnership; Problems with the regional infrastructure and transport accessibility to the regions of Russia; Rather long period of tourism cluster launch (aver-age 3 years) In Figure 1 we showed a generalized tourism cluster without dividing it into sectors in the region. Thus, the development of cluster-based tourism in Rus-sia is rather important and timely issue. STUDY AREA The focus of our research are the regions, located in the central Russia and included into the project Velikaya Volga (The Great Volga). Nowadays, the Russian regions face the challenge of developing common principles for the tourist product promotion.

Figure 1: Generalized scheme of a tourism cluster

Journal of Applied Engineering Science 14(2016)1, 354

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

Tourists are mainly aware of Moscow and Saint Petersburg locations, included in the cluster the Golden Ring of Russia , the Silver Ring of Russia . International tourists are not aware of the potential of the new cluster evolved around the Volga River. A new recognizable brand and a new itinerary is developed based on the historical and cultur-al monuments of the Bronze Century (so called, Bronze Ring ), rather than traditional for Russia church theme, extensively exploited in Golden and Silver Rings . Velikaya Volga cluster is a joint investment project in tourism and recreational sector of the Volga Region. The cluster is included into the Federal Target Programme Development of domestic and incoming tourism in the Russian Federation for 2011-2018 . Joining specially protected nature territories, located on the banks of the Volga and the Kama Rivers, into interregional cluster, acts as an additional incentive for the development of cruise tourism in the district. The information on the po-tential of a new Volga and Kama cluster is disseminated through the information space of the tourist companies in the Volga Region. The emerging cluster is still very young and the potential of the cluster, which includes eight subjects of the Russian Federation, is still to be unlocked. Interregional tourism cluster includes the fol-lowing partners: Samara Region, Nizhny Novgorod Re-gion, Ulyanovsk Region, Saratov Region, Penza Region, Chuvash Republic, Republic of Tatarstan and Mari El Republic [16]. First the Custer Agreement on Cooperation was officially announced in June 2011. The initia-tive was supported by the Federal Agency for Tourism by sponsoring a media tour around the cities of the clus-ter, which provided the grounds for implementation a number of business projects aimed at Volga tourism development. One of the projects includes producing printed promotional products, creating a single exhibi-tion stand branded as Velikaya Volga (The Great Vol-ga River) at the Intourmarket exhibition. METHODS The novelty of the research is achieved by wellgrounded comparative efficiency of tourism potential implementation in the regions included in the interregional cluster. The detailed methods are applicable to the efficiency comparison of several different clusters. The authors method of evaluation of the tourism potential efficiency 64

assumes the following algorithm. The source data for the analysis of the tourism cluster comparative efficiency may be expert evaluation of the potential of the tourist area under research and statistical data, presented on the regional and national levels. Rus-sian rating agency Expert RA is one of the most au-thoritative rating agencies in Russia, which has consid-ered the regional tourism potential for the past decade. It is important to note one requirement used to evaluate tourism potential: this evaluation should be carried out based on the complex approach to the choice of factors, and with the application of the weighted average of the expert opinion. In this respect the method of tourism potential evaluation, carried out by the Expert RA agency meets the above mentioned requirements [05]. What concerns statistical data in the field of tourism, necessary for the comparative evaluation, we can refer to the data, provided by the Russian Tourism Associa-tion and the Federal State Service of Statistics of the Russian Federation depending on the profit-making ca-pacity gained from the charged tourist services, hotel, catering, types of hotel rooms, number of arrivals and accommodations of national and international tourists. Data on the expenditure component in the field of tour-ism in the regions can be obtained from regional and republic target programmes of tourism development, published on the websites of the tourism ministries in the regions of the Russian Federation. The regions undergoing analysis are rated based on their annual (monthly) indicators, taking into consideration revenues and expenditures. Different types of graphs and charts can be constructed based on the rating results. For example, graphs, showing the results of regions rating in terms of their tourism potential, graphs, showing the amount of revenue, obtained from the charged tourist services and objects in the regions. Thus, the axis of abscissas contains the values with the regional invest-ments, while the axis of the ordinates contains indicators corresponding to the target characteristics of the above described graphs. The overriding criteria of every graph efficiency may be indicators, characterizing the level of investment with the level of revenue or potential eco-nomic efficiency of tourism in the regions. This charac-teristics may be validated by fixing a line splitting all the rating results into two categories. The first category of tourist objects found above the threshold line Journal of Applied Engineering Science 14(2016)1, 354

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

considered as meeting the expected outcomes, while the objects found below the line do not meet the expected outcomes, thus, need to be improved. The groups defined as a result of such analysis, may be classified as leading, average and low. Every group may have its own ways of efficiency enhancement. In our research we analyzed the use of tourism potential based on the case study of one of the regions included in the cluster Velikaya Volga (The Great Volga). In compliance with the criteria, developed by Expert-RA , four parameters should be considered in evaluating the tourism potential: 1) nature and recreational complex; 2) historical and cultural complex, 3) development of tourist accommodation network and 4) entertainment facilities. The first two act as a driving force, that fosters a tourist to visit a certain tourist destination, while the other two represent the conditions for keeping the tour-ists in the region and stimulate their financial contribu-tions. In the expert opinion the optimum combination and proportionate development of these two elements of tourism is capable of making this tourist destination attractive for visitors. Table 1: Dynamics of the tourism potential in the regions, included into the Velikaya Volga cluster

2007

2008

2009

Ulyanovsk Region

2006

Chuvash Republic

2010

2011

2012

2013

Mari El Republic

Penza Region

Saratov Region

Samara Region

2005

Nizhny Novgorod Region

Year

Republic of Tatarstan

Tourism potential rank in compliance with Expert-RA evaluation

RESULTS The number of the subjects of the Russian Federation varied throughout the last decade from 88 Journal of Applied Engineering Science 14(2016)1, 354

in 2005 to 83 in 2013. In compliance with the estimate, provided by Expert-RA agency, the best indicators of the regions correspond to the lowest rank values. All through this decade the leading positions were taken by the same regions. The regions with the highest tourism potential are the following: Republic of Tatarstan, Nizhny Novgorod Region, Samara Region. The regions with the average tourism potential include Saratov Region and Chuvash Republic. The regions with the low tourism potential include Penza Region, Ulyanovsk region, Mari El Republic. In our research we estimated the division of the subjects of the Volga region with regard to their tourism attrac-tion. Deterioration of the indicators in the last five years demonstrated the following regions: Saratov Region by three points, Mari El Republic by seven points, Penza Region by 18 points, and the highest loss demonstrat-ed Ulyanovsk Region by 26 points in the tourism po-tential rank. (!" #$%&#'*$ %+%*"/$ <="!&+. Among the reasons are the deterioration in the conditions of the nature and recreation environment, lack of due atten-tion to historical and cultural complexes and to the development of tourism infrastructure. For the past five years a few regions have improved their position, i.e. the Republic of Tatarstan by 1 point, Chuvash Republic by 7 points. The improvements in most cases take place due to the following factors: host-ing significant events with wide media coverage, creating new places for recreation and entertainment, develop-ment of accommodation network in the regions. One of the most important indicators used for the evaluation of the cluster development is the profitability capacity of the region. The issue of timely access to the statistical tourism data has been frequently addressed. However, only recently, Russian Federal Agency for Tourism has published the summary statistics for the past 5 years [11]. In terms of the revenue gained from the provided charged services the leading position are taken by Nizhny Novgorod Region, the Republic of Ta-tarstan and Samara Region. The amount of the charged tourist services provided for the past five years is given in Table 2. Our analysis showed, that a few regions included into the cluster have improved their revenue values. Thus, in 2012 significant improvements were noted in Nizhny Novgorod Region, Ulyanovsk Region (by 42>), Penza Region and Mari El Republic (by 33>), the Republic of Ta65

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

tarstan (by 28%). In 2013 significant growth rate of the charged services was noted in the following regions: Nizhny Novgorod Region (by 46%), Ulyanovsk Region (by 31%). A few regions demonstrated rather moderate growth rates in 2013. These include Samara Region (by 13%), Saratov Region (by 3 %). In our research we compared the tourism potential rank and the rank of profitability of the regions included in the cluster Velikaya Volga . The position chart below distributes the regions into groups depending on the correlation between tourism profitability rank and the tourism potential of the region. In Figure 2 the regions are defined as follows: 1 the Republic of Tatarstan; 2 Nizhny Novgorod Region; 3 Samara Region; 4 Saratov Region; 5 Chuvash Republic; 6 Penza Region; 7 Ulyanovsk Region; 8 Mari El Republic Table 2: Revenue gained from charged tourist services in the regions, included into the Velikaya Volga cluster, mln rubles

Figure 2: Use of tourism potential by the regions included into Velikaya Volga cluster

The regions, located below the line do not use their tour-ism potential to its full capacity. These are Penza Region and Saratov Region, the rank values mismatch. This is one of the factors which hinders the tourist attraction of these regions, thus, requires a complex of activities to create more favorable conditions in these regions in order to attract investors and entrepreneurs. In Ulyanovsk Region and Chuvash Republic the profitability value is one point higher than the tourism potential level. In the Republic of Tatarstan, Mari El Republic, Nizhny Novgo-rod Region and Samara Region the ranks of tourism potential and revenue match, which means relatively high degree of tourism potential implementation in these regions.

Region

2011

2012

2013

Nizhny Novgorod Region

2731

3866

5634

Republic of Tatarstan

1509

1932

2313

Samara Region

1447

1624

1832

Saratov Region

1474

1408

1453

CONCLUSION

Ulyanovsk Region

700

996

1305

Penza Region

446

590

719

Mari El Republic

431

573

700

Chuvash Republic

542

596

691

Thus, the regions of the central Russia, included in our research, have featured positive dynamics in terms of tourism revenue in the recent years. Nevertheless, the following challenges have been identified: not all the regions make sufficient contributions in the tourism sec-tor. In this case the tourism potential is underused. The comparative evaluation of tourism potential efficiency in the partner regions, included into the cluster Velikaya Volga shows that interregional cluster exists due to the efforts and contributions of the leading regions, while the other regions do not contribute their creative, investment share into the cluster development. Positive tendency in this respect is demonstrated by the Republic of Tatarstan, Samara Region and Nizhny Novgorod Region. Success of these regions on the tourism market is provided by well grounded programmes for tourism development. However, longterm development programmes do not guarantee unexpected success on the tourism market to the newcomer regions. In our

Table 3: Analysis of tourism potential use by the regions included into Velikaya Volga cluster Tourism potential rank

Revenue rank

Republic of Tatarstan

Chuvash Republic

Nizhny Novgorod Region

Penza Region

Samara Region

Ulyanovsk Region

Mari El Republic

Saratov Region

Volga regions

Journal of Applied Engineering Science 14(2016)1, 354

Vera Rukomoinikova - Development of cluster approuch in tourism (Russia case study)

research this experience is demonstrated by Chuvash Republic and Ulyanovsk Region. It is advisable to stimulate the regions, which feature low contributions in tourism, to take into consideration the experience of the leading regions and realize their tourism potential to the full. We believe that comparative analysis of the tourism potential efficiency in the partner-regions included into the tourism cluster will allow activating regional tourism development and solving the problems identified. ACKNOWLEDGEMENTS The article was published with the financial support from the Ministry of Education and Science of the Rus-sian Federation within the framework of state supported project ! 26.1378.2014/" Sociocultural resources of modernization in the efficiency evaluation of the territo-ry development strategic programs in the context of domestic tourism. REFERENCES 1) 18th General assembly of the World Tourism Or-ganization (UNWTO) completed its work in Asta-na // Tourism news. Available at http://www.indigotur.ru/tnews/6/ date of reference 12.10.2009. 2) Aleksandrova, A. 2007. Tourism clusters: contents, borders, operating mechanism // Contemporary prob-lems of service and tourism. No 1. P. 51 61. 3) Buryatia tourism cluster. Baikal tourism alliance // 2007, 25 May. P. 5 Available at http:// www.nbrb.ru/books/element.php?ID=2754 Date of Reference 16.01.2010. 4) Frangially, Fr. 2010. World Tourism: global and region review. Paris, Roma: UNWTO, 176 pp. 5) Investment ratings of Russian regions [Electronic resource]. URL: http://raexpert. ru/rankings/#r_1108 (date of reference 15.01.2015). 6) Jackson, J., Houghton, M., Russell, R., and Triandos, P. 2005. Innovations in Measuring Economic Impacts of Regional Festivals: A Do It-Yourself-Kit. Journal of Travel Research, 43, 360-367. 7) Krajnovi$ A. 2013. Model for Tourism Clusterisation of Dalmatia as the Umbrella Brand // Economica Jadertina 2, 74-89. 8) Leading countries in the Travel & Tourism Com-petitiveness Index (TTCI) in 2015 Journal of Applied Engineering Science 14(2016)1, 354

Available at http://www.statista.com/statistics/186639/best-ranked-countries-in-thetravel-and-tourism-competetiveness-index/ date of reference 30.09.2015. 9) Porter, M. 1990. The competitive advantage of na-tions. New York: The Free press, 270 p. 10) Porter, M. 2001. Competition Moscow: Publishing House Williams , 495 p. P. 207. 11) Russian Agency for Tourism. Generalized data for the past 5 years (from 2009 to 2013 ) by the subjects of the Russian Federation. [electronic resource]. URL: http://www. russiatourism.ru/content/8/section/81/detail/4124/ (date of reference 15.01.2015). 12) Santos S. 2009. The tourism clusters role in regional development: presenting a competitiveness conceptual model // Tourism Destination Development and Branding, Eilat, 127-139. 13) Shabalina N.V. Introduction into tourism cluster-ing available at http://bzm.su/articles/ article-05 (date of reference 22.01.2012). 14) Sharpley, R. 2002. The Challenges of Economic Diver-sification Through Tourism: The Case of Abu Dhabi. International Journal Tourism Research, 4, 221-235. 15) Simmie, J. 2004. Innovation and Clustering in the Globalised International Economy. Urban Studies, 41(5/6), 1095-1112. 16) Velikaya Volga. [electronic resource]. URL: http://greatvolga.com/ (date of reference 24.05.2015) Paper sent to revision: 26.01.2016. Paper ready for publication: 10.02.2016.

Original Scientific Paper

doi:10.5937/jaes14-10123

Paper number: 14(2016)1, 355, 68 - 74

PRACTICAL ASPECTS OF REALIZATION OF THE DEVELOPMENT STRATEGY IN THE TOURISM REGION Vera Rukomoinikova* Volga State University of Technology, Yoshkar-Ola, Russia Nadezhda Zykova Volga State University of Technology, Yoshkar-Ola, Russia Iraida Tumbaeva Volga State University of Technology, Yoshkar-Ola, Russia Many authors have turned their research interests to the problem of efficiency of the tourism development strategy realization. It was the result of the fact that growth and implementation of the tourism development strategies appears to be the common world trend of the last decade. This research focuses on the territorial level. The paper concentrates on the small region of the central part of Russia through the example of which the authors want to retrace the realization of the tourism development strategy adopted by the municipal authorities. The major aim of the study has several objectives associated with the theoretical analysis of practical aspects of the tourism development prob-lem in the region. First of all, there is a need to provide a review of the literature devoted to the regional tourism efficiency evaluation. Secondly, it is necessary to measure the tourism efficiency in the region on the quantitative and qualitative level. The quantitative level re-fers to statistic data about the regional tourism. The qualitative level includes case study with self-employed individuals who set up their business in the field of rural tourism. Finally, this study has an overarching objective to identify the opportunities for the touristic potential of the small agricultural region of Mari El. It is quite currently important for the region to reveal the patterns according to which an inser-tion of private sector in the rural tourism development takes place. The research is based on international academic literature and the analysis of Russian experience. Key words: Tourism development strategy, Long-term tourism development programs, Performance indicators, Cluster, Tourist destina-tion INTRODUCTION A strategic plan of management of the touristic sphere is important for the long term success in tourism development. Creation of successful strategic plan for tourism requires an application of the overall approach to the management of the region (tourism destination). The strategic plan should be developed on the base of analy-sis evaluation of the situation in the process of planning, including the review of service consumersÂ&#x2019; markets, operational surroundings, resources potential, existing products and environment. Strategic planning for the touristic sphere is a cyclical process which requires con-stant monitoring, reviewing and flexibility for adaptation to changing conditions. The questions of the development of tourism strat-

egies for countries and regions of the world as well as the questions of the domestic tourism level are considered on the official site of World Tourism Organization (UN-WTO). The site presents a short instruction of the devel-opment of tourism strategies. The objective of the stra-tegic program is defined as following: to define the foundation of the longterm development for tourism (10-20 years) with an accent on politics and strategies, planning, institutional consolidation of legislation and regulation, production development and its diversifica-tion, marketing and promotion, touristic infrastructure and overbuilding, economical impact of tourism on in-vestments in tourism, development of human resources and socio-cultural and ecological consequences of tourism. The gradual plan of realization of tourism development strategies consists of three stages: de-

* Volga State University of Technology, Yoshkar-Ola, Russia (424000, Yoshkar-Ola, Lenin Square, 3; RukomoinikovaVP@volgatech.net

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

velopment of program scenario, detailed elaboration of master plan for every sector of touristic industry, realization of actions by means of technical assistance and financing (ration up to 150 thousand euro) from the side of WTO. Strategic plans are elaborated not only for development of the tourism sphere of the country on the whole but in certain touristic directions such as: rural tourism, tourism of local communities, mountain tourism, coastal tour-ism, eco-tourism, spa tourism. The theory and practice of development and implemen-tation of strategic programs of tourism development in the countries of the world are concentrated on the open resource Sustainable Tourism Online. The developer of this resource is Australia s Sustainable Tourism Cooperative Research Centre (STCRC). We will recite several important conclusions on the development of strategic plans and programs of tourism development presented by the Australian research centre. Development of stra-tegic touristic plan deals with the determination of stra-tegic priorities and directions which are revealed by con-cerned parties for planning, development management and marketing in the region. The STCRC researches consider the following to be the necessary conditions for tourism strategy realization: to identify specific respon-sibilities and time limits for realization of strategies and actions of concerned parties; to specify particular aims and measures for achievement of a strategic plan; to carry out regular monitoring and control over implementation of the strategy realization program; to develop tourism strategy as alive document which can be adapted and updated in case of operational surround-ings changes. The next step of our research was the analysis of strate-gies and plans of development of tourism in the countries of Europe, America, Australia, Asia, Africa and Pacific Region. It is possible to come to some conclu-sions [14]. First, the absolute majority of documents was developed and implemented during the last decade. A small amount of countries that develop tourism on the governmental level has a long period of realization of program approach to the goals of the touristic sphere. It indicates that the sphere of tourism has started to take leading positions in national economies comparatively not long ago: at the turn of the century and till present. Second, a number of analyzed strategies of tourJournal of Applied Engineering Science 14(2016)1, 355

ism development can be distinguished by a detailed reasoned approach to realization of shaped plans, some programs have a declarative character. Nevertheless, practically all programs have a high level of governmental assistance. Third, some countries realize development strategies not only on the national level but on the regional and munic-ipal levels as well. Moreover, the latter is noted for a high degree of details forethought. Fourth, not all programs have a financial part that makes difficult their realization. Some strategies claim to achieve ambitious goals, but the indices of investments are either absent at all or not quite real. On the whole, we can conclude that development and implementation of strategies of tourism development appears to be the common world trend of the last dec-ade. METHODOLOGY OF THE EFFICIENCY RE-SEARCH OF THE TOURISM STRATEGIES REALIZATION As for the methods of evaluation which form the basis of tourism efficiency, the following various methods are offered: the method of expert estimation based on the heuristic approach of Delphi [01], the method of hierarchy Analytic Hierarchy Process [02], methods of grading Superiority and Inferiority Ranking Method, the method of average weighted estimates Weighted Sum Model [03], the method of additive optimization Optimized Restricted Additive Methods [11]. In relation to the target audience various factors should be taken into account: tourists from different regions of the same country can be more demanding to the quality of certain factors which compose touristic attraction of the region. For example, it can be the quality of the road service or informational support of tourism [12]. In this case it is often necessary to revaluate significance of factors in-cluded into estimation of the potential [10]. Importance of the problem of tourist resources estimation is highlighted in the Federal Target Program Development of domestic and incoming tourism in the Russian Federation in 2011 - 2016 years [07]. Tourist potential of any area consists of natural and manmade objects and phenomena as well as of conditions, possibilities and means, necessary and suitable for the tourist product formation. Scientific conceptions 69

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

of the tourist potential estimation offer a complex list of factors: natural and climatic resources ( weather conditions, landscape, water and mineral resources, flora, fauna, certain natural monuments and others), historical cultural resources (material and nonmaterial cultural heritage of the region) and socio economical resources (infrastructure of the touristic sector, managerial, human and educational, material, financial and informational resources and conditions). One can find interesting famous methods of estimation of tourist-recreational potential of territories that were elaborated by Aleksandrova A.Y., Drozdov A.V., Robinson B.V. and others. Ushakova E.O., Selivanov I.A. and others also suggest attractive patterns of complex estimation of tourist resources. An integrated evaluation model of tourist resources was proposed by Sarancha M.A. Results of tourist potential evaluation of the territory are presented in the tourist passport of the region. Federal Tourist Agency of the Russian Federation specifies requirements for the touris-tic passport of every region (territory) as regular and constantly renewing document. We will mention only some publications on evaluation of tourist potential by the example of certain regions: Khudenkhih Y.A. Ap-proaches to evaluation of tourist potential of the territo-ry by example of regions of Perm kray , Karchevskaya E.N. Methodological support of regional development and dimensional differentiation of tourism (by example of the Gomel region) , Kumova N.A. Complex evalua-tion of tourist-recreational potential (by the example of the Kursk region) , Barsukova O.N. Marketing evalua-tion of tourist potential (by the example of the tourist centre of Tobolsk) and others. As for evaluation of potential realization, researchers are mostly concentrated on economic methods of evaluation: increase of money receipts from tourism, raise of employment level, growth of income of local population and other economic results. Marketing and PR-factors also take part in evaluation of potential realization: increase of awareness about destination, growth of posi-tive feedbacks from tourists, degree of place s attraction, number of brand images in the consciousness of potential tourists. Critical effects of development of tourist potential are also taken into account, particularly, environmental impact: use of water, power consump-tion, release of wastes in the recreation area by guests. The following facts are compared, for example: 70

tourist in Spain uses 880 liters of water per day against 250 liters used by locals [15]. An analysis of regional and municipal Russian tourist legislation demonstrates that the problem of estimation of efficiency of tourist potential realization is not less important on this level too, since there are no regional legislatives acts with clear instructions about methods of evaluation. Regional programs of tourism development as usual contain planned figures of program realization, such as: number of promotional and informational materials about tourist potential, number of Russian and international of specialized exhibitions, number of pro-motional and informational tours for Russian and for-eign mass media and tour operators, number of tourist informational terminals, number of tourists visiting the region, amount of touristic services, amount of invest-ments which were drawn as part of governmental financial support in the form of interests refund of loans giv-en by commercial banks on the infrastructure develop-ment. APPLYING OF THE PROGRAM APPROACH IN THE STRATEGY OF TOURISM DEVELOPMENT IN RUSSIA In the last decade in Russia the questions of rise of strategic planning of the territory are discussed more frequently. Close attention is paid to the sphere of tourism: corresponding regulatory acts are being adopted, programs of development of tourist recreational centers are being created. In order to stimulate the development of different spheres governmental authorities realize a se-ries of actions which is mostly regulated by a legal act adopted at one or another level of governmental power (municipal, regional, federal). This approach can be called program-oriented or system and goal oriented, since legal acts that approve targeted programs consist of strictly defined set of appendices, where each appendix contain a series of actions, amount of financing of these actions and indices of actions efficiency. Every program specifies its objectives, results and actions efficiency indices. It should be noted that all regions in Rus-sia adopt such legal acts which sanction republican and regional targeted programs of development of domestic and incoming tourism. In the process of investigation of tourism strategy development of the Russian Federation [5] we used the program approach which admits that in Journal of Applied Engineering Science 14(2016)1, 355

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

virtue of environment instability a targeted situation will again take in certain problems; the solution of these problems can t be found in advance. At the level of the territorial entities of the Russian Federation we developed a spatial model of cluster organization of tourism on the basis of determi-nation of territories having unique natural recreational and historical-cultural potential. These territories are considered as places for realization of cluster tourist ini-tiatives and formation of local tourist clusters. Govern-mental support of cluster initiatives is becoming a part of governmental strategy of increase of the Russian competitiveness in the sphere of tourism. In the Strategy of tourism development in the Russian Federation till 2020 there is an interesting analysis of tourist potential of the regions of Russia according to federal districts. Today most territorial entities of the Russian Federation understand and admit significance of elaboration and implementation of programs of tour-ism development, however, the majority of projects is concentrated in Central, Northwestern and Volga dis-tricts as well as around famous tourist attractions in Siberia and Russian Far East. The amount of financing of actions is included into the programs of Russian regions with account of finances from republican and federal budgets. In addition regions can rely on federal budget resources in case of insertion of tourist recreational projects and clusters in the federal targeted program of tourism development. Amounts of program financing by virtue of local budget resources usually have a forecasting character and are précised for every next year taking into account possibil-ities of budget of a particular region. Efficiency of strategic programs of tourism development is manifested at the state level (creation of new working places, increase in taxes, attraction of investments) as well as at the regional level (decrease in social tension, solution of questions of ecological safety, improvement of infrastructure). Efficiency of activity of particular touristic businesses is estimated in marketing categories volume and profitability of sales, advertising performance, business competitiveness, capital productivity, material productivity, coefficient of productive capacity use. Overall evaluation of efficiency of regional tourist potential use has to reveal the indices which characterize production structure of association, investment and in-novaJournal of Applied Engineering Science 14(2016)1, 355

tive activity as well as economic indices: balance profit, sales proceeds, profitability. As can be seen from the above one of the important indicators of evaluation of strategic programs results in the sphere of tourism are the earning yield of the field. EFFICIENCY OF THE TOURISM DEVELOPMENT PROGRAM BY THE EXAMPLE OF THE MARI EL REGION Through the example of the region of Mari El we will review realization of tourism strategy. Mari El is a small in population size (687 435 people) region in the central part of Russia with a lower rate of urban population (65, 19%), the main types of settlements are rural and small towns. According to researches the region has been in the state of modernization of the second type for a long time. It can be characterized by stagnation (growth without evolution); one of the reasons for this stagnation is imbalance of modernization parameters by reason of notice-able retardation of components of economical and cog-nitive indicators. The republic has not overcome the consequences of industrial failure in the 90th years of the XX century yet. The republic takes actions for diversifi-cation of economy, in particular, it is the adoption of the targeted program Development of tourism in the repub-lic of Mari El for 2011-2016 years . At present the re-public possesses a quite high tourist potential, as well as intrinsic prerequisites for its development. Mari El is considered to be a region where authentic culture and traditions still exist; Mari people have saved till today Finno Ugric customs, traditions, religion and rites. It is the only nation in Europe which has the paganism as an official religion. In the republic there are several hundreds of Sacred groves, some of them are protected by the state. Natural recreational complex of the republic includes a big amount of small rivers and lakes, 2 nature reserves: Bolshaya Kokshaga and Mari Chodra . All these factors give possibilities for development of cultural-cognitive, ecological and rural tourism. In the republic there are 66 tour operators and travel agencies, the infrastructure includes 40 hotels and quest houses, 4 hostels, 30 health resorts, 9 tourist complexes and 18 recreational centers, 6 sports facilities, 20 sport clubs and fitness centers, 9 sports complexes and stadiums, 6 museums, 6 entertainment centers and 71

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

complex-es, 3 cinema theatres. By estimate of the Committee on tourism of the republic of Mari El in 2014 domestic and incoming tourism flows (inclusive of sightseers) consti-tute 422,3 thousand people, foreign residents 6,6 thousand people, international tourism 15 thousand people [6]. Herein after, we will show the statistics of tourist profitability for the last 5 years. As can be noted from the above tables, number of tour-ist arrivals decreases while profitability indices increase due to the price advance and not to the number of arriv-ing people. The program of Mari El tourism for 6 years includes 215 million rubles of financial investments with account of governmental and private investments. The long term perspectives on the territory of the republic featuring private investors allows for creation and de-velopment of tourist-recreational clusters Tsar-grad in Yoshkar-Ola and Volgydo in Zvenigovsky and Gornomariysky regions and in Kozmodemiansk. The pro-jects listed above are included into the list of actions of the federal program Development of domestic and incoming tourism in the Russian Federation , where the total amount of investments within the frame of clusters creation is more than 4 billion rubles. Nowadays on the territory of the republic a number of projects on devel-opment of domestic and incoming tourism and creation of necessary infrastructure are already realizing or planned to be realized in the nearest future. Among these projects we can mention formation of Mari tourist village Vizimbir in Kuzhenersky Region, eco-tourist complex Chodyrayal in Volzhsky Region, tourist complexes Volgavita , Okolitsa and Dvoryanskoe gnezdo in Kilemarsky Region.

The authors of the paper believe that it is necessary to pay more attention to the development of rural tourism. Rural tourism includes all types of pastime of city dwellers in the countryside, i.e. elements of rest and health activities, ethnographic excursions. At present development of this type of tourism is regard-ed as one of directions of innovative development of the agricultural center which enables to solve socio-cultural problems of rural population, to increase cultural and educational levels of rural population, stimulates preser-vation of local customs and folk crafts. The last decade of the XX century saw an increasing interest to ecologi-cal and rural tourism [13]. Among the Volga regions Chuvash Republic and the Penza Region are extensively developing this tourist destination. RESULTS ANALYSIS OF CASE STUDY WITH ENTREPRENEURS OF THE RURAL TOURISM IN MARI EL An empiric foundation includes statistics of qualitative underlying interviews with ten private entrepreneurs of 3 regions of Mari El. In the context of our research we conducted inquiries in 3 human settlements of Mari El: the villages of Maliy Kugunur (Orshansky Region), Aleshkino (Kilemarsky Region), Oshutyaly (Zvenigov-sky Region). The choice of human settlements in our research was determined by the fact that there were en-trepreneurs developing rural tourism. In the village of Maliy Kugunur there is a tourist complex country estate Tihie zori , in Aleshkinotourist complex Razdo-lie in Oshutyal tourist camp Yushut .

Table 1: Income from tourism in Mari El, millions of rubles [08] Tourism profitability indices in Mari El

2009 year

2010 year

2011 year

2012 year

2013 year

Amount of touristic services

261

315

431

573

700

Profitability turnover of hotels and restaurants

1451

1662

2125

2252

2455

Table 2: Dynamics of number of employees in the field of tourism and tourist arrivals in Mari El, thousands of people Statistic indices in the field of tourism in Mari El

2009 year

2010 year

2011 year

2012 year

2013 year

Number of travel agencies employees

0,1

0,15

0,16

0,12

0,1

Number of hotels and restaurants employees

2,8

2,7

3,6

3,9

3,6

Number of Russian citizens housed incommunal places of accommodation

111,1

101,3

102,1

104,6

100,9

Number of foreign citizens housed in communal places of accommodation

1,0

1,1

1,3

1,2

Journal of Applied Engineering Science 14(2016)1, 355

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

All enterprises are considered as small business , steadily work on the market of tourist services more than 3 years, actively present their services as rural tourism and can be named as typical examples in this sphere. Non formalized interviews which were conducted with entrepreneurs and heads of enterprises made it possible to reveal some characteristics of their motivation and interaction with population. The entrepreneurs came to the sphere of rural tourism having significant experience in other fields of business and commercial structures. Their age is more than the average; one of the motives was a wish to leave the hustle and bustle of the city , but at the same time to continue an active lifestyle and to be helpful for people and society , to maintain the movement for villages revival in Russia , develop and maintain the national culture of the Mari nation . A social component in the motivation of entrepreneurs stipulates their positive attitude to the local society. In the context of our research we defined two models of entrepreneurship in the country. The first model is con-sumer-oriented when an entrepreneur is focused on rural resources and doesn t have much impact on the local infrastructure. An entrepreneur has only economic influ-ence assistance to the employment of local popula-tion. For example, owner of the country estate Tihie zori , an entrepreneur, wasn t acquainted with traditions and culture of the local society. The reasons for the con-struction of the complex are beautiful and clean locality as well as availability of workforce from the nearby vil-lage. The second model is called socio-cultural, when an en-trepreneur consciously specifies the task to encourage economical and socio-cultural development of the local community. It can be realized through traditional folk and ethno-cultural values: organization and carrying of festivals and holidays in the country. For example, the festival Ancestral lands is very popular in Kilemarsky Region. This festival was initiated by the director of the quest house Razdolie . Later on, starting from the second year the festival was supported at the governmental level and became all republican. Let s cite another example of social activity of an entre-preneur in the field of rural tourism. The director of the tourist camp Yushut set up his business with the aid of employment bureau in 2011. In the past during his Sovi-et childhood he attended the groups of tourism for chil-dren and Journal of Applied Engineering Science 14(2016)1, 355

young people. That s why while choosing an area for a tourist camp he initially thought about an appropriate place for rafting. Moreover, he is interested in development of youth movements. He became one of the organizers of the Forum of young entrepreneurs of Zvenigovsky Region within the frames of republican targeted program Involvement of young people into the entrepreneurial activity in the Republic of Mari El in 20112015 . He cordially hosted and accommodated all participants of the forum in his tourist camp in the vil-lage of Oshutyaly, Zvenigovsky Region. For one year and a half he managed to turn a deserted country estate in Oshutyaly into a stable enterprise specialized in coun-try-tourism. He actively shares his experience on the development of rural tourism in Zvenigovsky Region and considers it to be an advantageous course in the sphere of tourism. He belongs to the group of entrepre-neurs who intensively search for new dimensions in the traditional past of Mari and Tatar people. CONCLUSION Research results make it possible to talk about two dif-ferent groups of business activity in the rural Tourism of Mari El. The beginning of business activity of different individuals was developing differently. It is evident that there are two different motivations. The founder of the quest complex Razdolie came back to her home village in order to revive it. She has already had the initial capital. The founder of the holiday camp Tihie zori hasn t belonged to the local community before. He made his choice and decided to set up business in the untouched ecological canton of Russia. In our research we called the two patterns of entrepreneur s interaction with local community as consumer oriented and pragmatic or sociallyoriented. Positive results of business activity for resident population were noted by local respondents (in one case the road was repaired while in the other case the shop was opened). Activity of such enthusiasts is typical for the initial phase of the development of new directions. There is no doubt that rural tourism is a relatively new direction in the Russian tourism. However, according to the world experience enthusiasts efforts are not enough to form a well-developed market of rural tourism services. It is possible to 73

Vera Rukomoinikova - Practical aspects of realization of the development strategy in the tourism region

reach the maximum effect in the rural tour-ism development relying on the foreign experience (Ita-ly, Greece, Cyprus). There were two stages of the rural tourism in these countries: 1) start-up for account of rural entrepreneurs activity; 2) results-oriented devel-opment by virtue of outside investments. At present de-velopment of the rural tourism in the republic of Mari El is on its first stage. For shifting to the second stage it is necessary to have governmental support in the form of development of goal-oriented programs and creation of favourable institutional environment. SUMMARY In our opinion in the rural tourism there are two patterns of value consciousness: the first deals with an individualistic structure of values; the second is a traditional one which is characterized with respect to traditions and ori-entation to family. Research results of rural entrepreneur s economical be-haviour allow coming to the conclusion that a transition to economical growth in rural tourism is directly con-nected with the evolution of enterprises of consumer-oriented type to the market side and extension of their business activity. The government aim is to create fa-vourable institutional conditions for activity regulation of the strongest businesses, support of potentially active ones and protection of socially weak subjects of the rural entrepreneurship. In this situation it is possible to expect an economical and social effect from the entre-preneurial sector that can result into rural areas devel-opment in Russia. ACKNOWLEDGEMENTS The article was published with the financial support from Ministry of Education and Science of the Russian Federation within the framework of state assignment to the project ! 26.1378.2014/ " Socio-cultural resources of modernization in the efficiency evaluation of the territory development strategic programs in the context of domestic tourism. REFERENCES 1) Cheng, F. 2008. Using the Delphi method to as-sess the potential of Taiwan s hot springs tourism sector. International Journal of Tourism Research, Vol. 10, Is-sue 4: 341 352. 2) Dwyer, L. & Kim, C. 2003. Destination Compet-itiveness: Determinants and Indicators. Current Issues in Tourism, 6(5), 369-414. 74

3) Henderson, J. C. (2006). Tourism in Dubai: Overcoming Barriers to Destination Development. Inter-national journal of Tourism Research, 8, 87-89. 4) http://cooperation.unwto.org/technical-product/tourism-development-master-plans-andstra tegicdevelopment-plans (date accessed 10/10/2015). 5) http://government.ru/docs/12933/ (date accessed 10/10/2015). 6) http://mari-el.gov.ru/komtur/Pages/plans. aspx (date accessed 10/10/2015). 7) http://www.programs-gov.ru/razvitieturizma (date accessed 10/10/2015). 8) http://www.russiatourism.ru/content/8/ section/81/detail/4124/ (date accessed 10/10/2015). 9) http://www.sustainabletourismonline.com/ destinations-and-communities/destinationplanning/planning-process/strategic-plan (date accessed 10/10/2015). 10) Iatu, C. & Bulai, M. (2011). New Approach in Evaluating Tourism Attractiveness in the Region of Moldavia (Romania). International Journal of Energy and Environment, 5, 165-174. 11) Mamun #. & Mitra S. (2012). A Methodology for Assessing Tourism Potential: Case Study Murshida-bad District, West Bengal, India. International Journal of Scientific and Research Publications, Vol. 2, Issue 9, 6-18. 12) Mill, R.C. & Morrison, A.M. (1999). The Tourism System. Dubuque, Iowa: Kendall Hunt Publishing Company. 350. 13) Nikolayeva, A.N., Khalilova, T.V., Rukomoinikova, V.P. 2015. The Concept of the Regional Industrial Cluster Information Support. Mediterranean Journal of Social Sciences. MCSER Publishing, Rome-Italy. Vol 6, No 2: 29-35. 14) Polukhina, A.N., Rukomoinikova, V.P. 2015. Evaluation of the tourism development strategic pro-grams efficiency (by the example of the Volga Federal District). Monograph, Yoshkar-Ola. Volga State Univer-sity of Technology. 15) Romero, R. & Homar V. 2012. Projections of the climate potential for tourism in Platja de Palma, Spain. International journal of Tourism Research, 11, 64-82. Paper sent to revision: 31.01.2016. Paper ready for publication: 22.02.2016. Journal of Applied Engineering Science 14(2016)1, 355

Original Scientific Paper

doi:10.5937/jaes14-10176

Paper number: 14(2016)1, 356, 75 - 83

DETECTION OF SYBIL S ACROSS COMMUNITIES OVER SOCIAL INTERNET OF THINGS A. Meena Kowshalya, Government College of Technology,Coimbatore, Tamil Nadu, India M.L.Valarmathi, Government College of Technology,Coimbatore, Tamil Nadu, India Social Internet of Things is a new paradigm that integrates Internet of things and Social Networks. Several challenges exist in building Social Internet of Things (SIoT). Very limited research has been carried out in the past 7 years to build a reliable Social Internet of Things community. A major threat with Social Things is Sybil attacks. Since SIoT is comprised of autonomous objects/nodes, tracking fake identities is an open problem. This paper proposes a new mechanism to identify Sybil s in communities of Social Internet of Things. This paper aims at (i) identifying communities among Social Internet of Things using Community_Infer algorithm. Using the properties of Social Networks and ACO heuristics various communities among the Social Internet of Things were identified. (ii) The communities are checked for existence of Sybil s. The algorithm Detect_Sybil detects and classifies the number of Sybil s in each communities. Compared to existing schemes the proposed method classifies communities accurately with a high modularity score. Key words: Node attributes similarity, Ant Colony Optimization, Community detection, Sybil detection INTRODUCTION Internet of Things has enabled integration of new heterogeneous technologies and communication standards. Social Networks (SN) are revolutions beyond Internet of Things (IoT). The convergence of IoT and Social Networks has paved way for a new paradigm called Social Internet of Things where not only humans collaborate but also objects. Objects in SIoT are autonomous and controlled via owners. SIoT environment is such an example for the 3rd ICT wave where object interact and collaborate to achieve the desired task. One of the many visions of IoT is to make objects not only smarter but also socially conscious. The authors in [06] defined Social Internet of Things as collection of intelligent objects. [25] has reported evolutions, applications, architecture, challenges and solutions for Internet of Things. Establishing a successful Social Internet of Things community is a complex task.

Challenges like Data Management, Data discovery, Interoperability, Trust Management, Security, Privacy, Heterogeneity, and Fault Tolerance has to be handled. Table 1 illustrates the difference between a Social network and a SIoT. The table show what humans do using a social network and what object does in a SIoT. SIoT objects mimic human behavior. [18] Suggests four kinds of social relationships between objects. The things can be engaged in (a) Parental object relationship defined by the same manufacturer among similar objects. (b) Co-location or Co-work objects relationship defined by objects which periodically or constantly reside in the same place. (c) Social object relationship established when objects come into contact when their owners do. (d) Ownership objects relationship established by objects of same owners. To establish a SIoT network, relationship and behavior of objects play an important role.

Table 1: Social network Vs Social Internet of Things Social Network

Social Internet of Things

Humans increase popularity and become visible

Objects publish information or services

Find new friends

Find new services and updates information

Get context information

Get environmental information / characteristics

* Southwest State University, st. 50 October, d.94, Kursk, Russia; swsu.ee@gmail.com

A. Meena Kowashalya - Detection of sibilÂ&#x2019;s across communities over social internet of things

[01] Proposed a widely accepted classification of social relationship among humans. The authors describe four relational structures namely communal sharing, equality matching, authority ranking and market pricing used to generate social actions. Community sharing can be associated with objects that have collective relevance ie., not relevant individually. Equality sharing represents relationship between objects that maintains their individuality and exchange information between objects that they consider as equals. Authority ranking relationship established between objects of different hierarchical level, for example a RFID reader and tag/ Master slave relationship. Market pricing relationship represents objects that work with other objects for mutual benefits. SIoT enables not only about human- human, human-object/node but also object/node Â&#x2013; object/node. The term object and node are interchangeably used in the paper, literally SIoT environments means node to be an object. The authors in [09] proved that the SIoT network is navigable and efficient service search can be done without affecting the application performance. This paper focuses on communal sharing and identifies communities in Social Internet of Things. Since the environment is open, major threat with such networks are Sybil attacks where many fake identities of objects are created to disrupt the reliability of network communication. This paper also detects SybilÂ&#x2019;s in the identified communities. The main contributions of this paper are: I. The communities in a Social Internet of Things are detected using the Community_ Infer algorithm. The algorithm uses Attributes of nodes to classify them as communities. The Ant Colony Optimization algorithm is employed along with node attribute similarity to efficiently detect communities. II. The Sybil_Detect algorithm detects number of Sybil nodes in the communities. Since honest nodes are fast mixing, there exists a cut between the Sybil region and the honest region. This simple strategy is used to detect the Sybil nodes in the communities. To the best of our knowledge this is the first work that detects Sybil nodes in a community. Compared with the existing schemes the Community detection algorithm and the Sybil detection algorithms are faster and accurate. The rest of the paper is organized as follows: Section 2 pres76

ents the related work, Section 3 discusses the proposed Community_Infer algorithm, Section 4 presents the proposed Sybil_Detect algorithm, and Section 5 discusses experimental results followed by Conclusion. RELATED WORKS Community Detection using ACO This section discusses the recent works in community detection using ACO. The authors in [20] defined a cluster by comparing it to a random graph. The degree distribution of the random graph was the same as that of the original graph. Community detection algorithms fall into two main categories namely modularity based and non modularity based. This paper focus only on modularity based algorithms. Modularity based algorithms are further divided into agglomerative based and divisive based. Divisive/ Agglomerative algorithms divide/aggregate nodes in a network into groups based on dissimilarities/ similarities. The authors in [24] proposed a computationally less expensive linear time algorithm to detect communities in large scale networks. [16] used a greedy heuristics to maximize the modularity score and obtain quality clustered communities. As an extension of [16], the authors in [03, 17, and 13] proposed improvements over the existing schemes that aimed to detect community structures based on quality modularity score. This paper uses the modularity concept of the existing algorithms and implements Ant colony Optimization heuristic technique for detection of communities. The collective behavior of ants to forage food resulted in communication between them by using their pheromone (chemicals deposited). This pheromone marks the path from the nest to the food and the same pheromone acts as a guide to other ants for the shortest path food. This technique is being used in Social Internet of Things where nodes/objects establish communication with each other directly or indirectly. To predict the social behavior of objects and to classify them ACO algorithm can be used. [08] proposed the first Ant Colony Optimization algorithm called the Ant system (AS). Several versions of ACO algorithms are proposed in the literature. The way pheromones are updated and the search procedures differ from algorithm to algorithm.

Journal of Applied Engineering Science 14(2016)1, 356

A. Meena Kowashalya - Detection of sibilÂ&#x2019;s across communities over social internet of things

Sybil Identification Recent literature has proposed many solutions to Sybil attacks. These approaches have been classified into three categories namely Sybil prevention methods, Social network based Sybil detection methods and Social network based Sybil tolerance methods. Sybil prevention approaches tries to reduce the number of false identities. Such approaches require a trusted central authority [22]. Social network based Sybil detection scheme can be further divided into three categories. 1. Trust based Sybil detection 2. Community based Sybil detection 3. Rank based Sybil detection [12, 11], [19] are the Trust based Sybil detection schemes that successfully identify and limit malicious identities created in a social network. Existing community based algorithms such as [03], [17] can be used to detect Sybil nodes in a social network. The only issue with these approaches is their faster mixing time. Sybil ranking mechanisms output a trust score for each node in a social network and differentiate Sybil and honest nodes by their trustworthiness. [13] uses degree normalization and trust propagation to detect Sybil nodes. Social network based Sybil tolerance schemes such as [04] relies on the graph structure features and application specific information of the network based on the above classification. Few recent Sybil defense mechanisms have been compared in table 2. [12, 11] proposed SybilGuard and SybilLimit, [10, 19, 27] proposed SybilInfer, SybilResilient and SybilDefender. All these protocols perform well when the topology is small and the algorithms are not computationally efficient. There is a need for a protocol that is computationally efficient and scalable that can handle millions of users. Sybil Guard [12] is a novel protocol that uses the concept of a cut between Sybil users and hon-

est users and exploits this property to bind the number of identities that a malicious user can create. This protocol relies on fast mixing property whereas the current social networks are not fast mixing. SybilLimit [11] is a defense mechanism against Sybil attacks using social networks. Compared to [12] which accepts O(!n logn) Sybil nodes per attack edge, [11] accepts only O(log n) Sybil nodes per attack edges. SybilLimit leverages independent instances of random routes to find short routes. Instead of exploiting intersection of edges between nodes it exploits intersection of edges which shows a significant improvement over SybilGuard. SybilInfer[10] uses Markov chain to transform a graph G into GÂ&#x2019; in order to maintain a uniform node distribution. It proves that the presence of Sybil nodes increases the mixing time of the graph. [19] is an improved protocol which is decentralized and outperforms [11] in terms of number of false negatives.[27] is a predecessor of [19] maintaining O(log n ) guarantee under sum up settings. Sybilproof [05] creates one DHT node for every node in the network for user identification. The performance of [05, 04] are the same, [04] uses user feedback and a centralized design to identify SybilÂ&#x2019;s. 3. Community Detection using ACO algorithm. The Social Internet of Things is represented as a graph G(V,E) where V is the set of vertices representing the nodes/objects, |V| = n and E represents the number of links between nodes |E| = e. The algorithm works by recursively dividing the graph into two. As a result, the resultant graph obtained is G1 and G2. Let the converged binary solution of ACO be c*. The original graph is partitioned only if the modularity value is high. The modularity score is calculated according to [20] as shown in equation 1. (1)

Table 2: Comparison of existing Sybil Defense mechanism Protocol

Honest Region

Technique

Design

SybilGuard [09]

Unbalanced

Random walk

Decentralized

SybilLimit [10]

Unbalanced

Random walk

Decentralized

SybilInfer [11]

Unbalanced

Random walk

Centralized

SybilResilient [12]

Balanced

Random walk and Breadth first search

Decentralized

SybilDefender [13]

Balanced

Random walk

Decentralized

Sybilproof [14]

Unbalanced

Random walk Distributed Hash Table

Decentralized

Ostra [15]

Unbalanced

User feedback

Centralized

Journal of Applied Engineering Science 14(2016)1, 356

A.!Meena!Kowashalya!-!Detection!of!sibil s!across!communities over!social!internet!of!things

bij is the excess number of edges between i and j ie., actual number of edges expected number of edges. All nodes are assigned a set of pheromone values ! = (!1, !2, ., !n) !i ant assigned to node i to group 1. As the iteration progresses, ants generates their solution based on their pheromone levels. The pheromone vector is updated to get better solution quality. The process is repeated until ! converges to the solution c*. The solution construction of the algorithm is simple. For each iteration t, every ant x constructs a solution solxt using !. The probability of constructing the solution is given by [20] as (2) The pheromone gets updated according to the equation (3) where is the evaporation factor. According to [06] it is proved that the pheromone values converge after a finite series of iterations. At the end of each iteration, convergence is checked. Community_Infer algorithm Algorithm: Community_Infer initialize =0, !i=0.4, Nant, T while t < T for all ants do solxt = construct solution (!) end for Update pheromone if convergence reset Calculate node attribute similarity Classify nodes into communities Node attributes similarity Node attribute based similarity is an efficient way of producing meaningful weights when compared to clustering coefficient similarity (CCS) and common neighbor similarity (CNS). For classifying the communities of the Social Internet of Things, node based attribute similarity can be employed since CCS and CNS are based on the network topology [15]. for each node i=1,2,3 .,n do for each node j=1,2, neighbors(i) do 78

w(i,j)=0 for each node attribute a do if a is nominal and i.a - j.a then w(i,j) = w(i,j) + 1 else if a is continuous then w(i,j) = w(i,j) + 1 " | i.a j.a | end if end for end for end for Sybil Node Detection: Sybil nodes are not as easy to detect and they disrupt the reliability of the network. Let G(V,E) be a graph consisting of V vertices and E edges. V is number of nodes in the network community and E represents the links between them. An initiator node is chosen to select two neighboring nodes randomly. The graph G(V,E) is comprised of set of imitator nodes v and their neighboring nodes. The algorithm for Sybil node detection is shown. Detect_Sybil algorithm Detect_Sybil (v) Input: Imitator node v Output: Honest nodes neighboring v 1. Select the init node N, let N chooses neighbors randomly 2. Initialize the community G(V,E) 3. Compute the position of nodes using the trilateration 4. For G(V,E) a. Perform Random walk through the community b. Find set of honest seeds using direct and indirect opinion 5. For each Hn a. Find nodes n whose frequency f >3 (threshold) b. Compute mean(ni) and standard deviation stddev(ni) 6. If mean ni > stddev then u is Sybil else u is honest Journal of Applied Engineering Science 14(2016)1, 356

A. Meena Kowashalya - Detection of sibil s across communities over social internet of things

The position of every node can be found using trilateration. The algorithm performs a random walk to find the number of honest seeds. This could be done by direct opinion and indirect recommendation of neighboring nodes. For each honest seed whose frequency is greater than 3, the mean and standard deviation are calculated. If the difference between mean and total honest seeds is greater than the standard deviation then the node is Sybil node. The edge between this node and the other honest node is labeled as attack edge. Thus this algorithm is repeated to find all Sybil nodes in the network. Direct and indirect opinions are in the range [0, 1].

communities and their smaller sub communities. Figure 5 and 6 shows the degree distribution and cumulative degree distribution for Zachary karate club. Figure 7 shows the local clustering coefficient for the same. Figure 8 represents the layout of the karate club and the detected communities. Due to dispute among node 1 and 34 the network spilt initially into two and later the algorithm detected 3 new sub communities. Table 3 illustrates the properties of the datasets. Graphml was used to generate graphical layouts of networks.

EXPERIMENTAL RESULTS Jazz Musicians [21] and Zachary s Karate club [26] was used for the experiments. SIoT is a dynamic environment where objects mimic human behavior, hence the basic assumption here is that things/objects move when their owners move. SWIM (Small World in Motion) was used to generate events of objects. Thus the datasets were modified accordingly to SIoT environment. [21] is the collaboration network between Jazz musicians. Each node is a Jazz musician and an edge denotes that two musicians have played together in a band. [26] is a Social network of friendships between 34 members of a karate club at a US university in the 1970. Figure 1 and Figure 2 shows the degree distribution and cumulative degree distribution for Jazz musician s dataset. The local clustering coefficient for the same is shown in figure 3. Figure 4 shows the layout of jazz musicians where the algorithm has detected 4 communities namely white and black

Figure 2: Cumulative degree distributions for Jazz musicians

Figure 3: Local clustering Coefficient for Jazz musicians

Figure 1: Degree distribution for Jazz musicians Journal of Applied Engineering Science 14(2016)1, 356

Figure 4: Four communities of Jazz musicians

A. Meena Kowashalya - Detection of sibilÂ&#x2019;s across communities over social internet of things

Figure 5: Degree distribution for Karate club

Figure 6: Cumulative degree distributions for Karate club

Figure 7: Local clustering Coefficient for Karate club

Figure 8: Five communities detected for Karate club

Table 3: Properties of Jazz musicians and Karate Club Property

Jazz Musicians

Karate Club

Vertices

198 vertices (musicians)

34 vertices (members)

Edges

2,742 edges (collaborations)

78 edges (ties)

Average degree

27.697 edges / vertex

4.5882 edges / vertex

Clustering coefficient

52.0%

25.6%

Diameter

6 edges

5 edges

Mean shortest path length

2.21 edges

2.44 edges

Table 4: Time taken by Community_Infer algorithm Network

Nodes

Time taken (seconds)

Karate Club

0.1 approximately

Jazz musicians

198

1.12

Table 4 shows the comparison of time taken by Community_Infer algorithm for Karate Club and Jazz musicians. 80

Journal of Applied Engineering Science 14(2016)1, 356

A. Meena Kowashalya - Detection of sibil s across communities over social internet of things

Table 5 presents the comparison of modularity scores and number of community detected across various algorithms. The proposed community_Infer algorithm detected 4 communities in both the networks and the modularity score of Jazz musicians showed substantial improvement over existing algorithms. To detect Sybil s in the community, one Sybil node in karate club and four Sybil s in Jazz musicians were induced at random. All other nodes are the honest nodes. The algorithm Detect_Sybil detected 1 Sybil for Karate club correctly and 5 Sybil s for Jazz musicians instead of 4. One honest node was identified as Sybil in Jazz musician s network. This false positive could be eliminated by improving the detection mechanism in the future. The running time of the algorithm was O(log n) and found to be efficient since Sybil detection was done inside communities. Existing algorithms for Sybil detection [12, 11, 10, 19, 27, 05, and 04] detect Sybil s on a whole network or sub network. This is the first attempt to find Sybil s based on Community of Interest of users. More security can also be imposed using attributed based encryption schemes [02].

CONCLUSION Social objects can be grouped easily based on their interest. Community detection is very crucial in Social Internet of Things. This paper detects communities in the SIoT environment using the Ant Colony Optimization heuristics and the node attribute similarity property. Sybil attacks are major threats in the current social environments. This paper eliminates Sybil nodes within communities. Compared to the existing schemes the proposed scheme detects communities efficiently with a high modularity score. The proposed Community_Infer has produced a modularity score of 0.419 and 0.617 for Karate Club and Jazz musicians respectively. Number of Communities detected was 4 and 5 for Karate Club and Jazz musicians respectively. The Detect_Sybil Algorithm detected accurately the 1 Sybil node for Karate Club and 5 Sybil nodes for Jazz musicians. Only 4 nodes in Jazz musicians were Sybil s. This false positive could be eliminated in the future by more accurate and powerful Sybil Detection schemes. Also, the same can be tested for large scale social networks.

Table 5: Comparison of modularity values and detected communities across various algorithms

Network

Nodes

External optimization [25]

Spectral partitioning [19]

ACO [24]

Community_ Infer

Modular- C o m m u - Modular- Commu- Modular- Commu- Modular- Commuity nity ity nity ity nity ity nity

Karate Club

0.419

Jazz musicians

198

0.445

0.595

0.617

Figure 9: Number of Sybil s and Honest nodes of Karate Club and Jazz Musicians Journal of Applied Engineering Science 14(2016)1, 356

A. Meena Kowashalya - Detection of sibil s across communities over social internet of things

REFERENCES 1) A. P. Fiske, The four elementary forms of sociality: framework for a unified theory of social relations, Psychological review, vol. 99, 1992. 2) A.MeenaKowshalya, Dr.M.L.Valarmathi, Secure and Efficient Ciphertext Policy Attribute Based Encryption without key Escrow Problem , International Journal of Emerging Engineering Research and Technology, Vol 2, No 2, pp:126-130, 2014. 3) Aaron Clauset,M.E.J.Newman, Cristopher Moore, Finding community structure in very large networks , Phys. Rev. E 70, 066111 ,2004. 4) Alan Mislove , Ansley Post , Peter Druschel , Krishna P. Gummadi, Ostra, leveraging trust to thwart unwanted communication , Proceedings of the 5th USENIX Symposium on Networked Systems Design and Implementation, pp.15-30, April 16-18, 2008, San Francisco, California 5) Alice Cheng , Eric Friedman, Sybilproof reputation mechanisms , Proceedings of the 2005 ACM SIGCOMM workshop on Economics of peer-to-peer systems, August 22-22, 2005, Philadelphia, Pennsylvania, USA 6) Bao.F and Chen.I.R, 2012 Dynamic Trust Management for the Internet of Things Applications , International Workshop on Self Aware IoT, San Jose, California, USA, pp:1-6. 7) Blum C, Dorigo M, the hypercube framework for Ant Colony Optimization, IEEE Transactions on Systems, Man, and Cybernetics, Vol 34, No 2, pp : 1161 1172, 2004. 8) Dorigo, M. Maniezzo, V. Colorni, A, Ant system: optimization by a colony of cooperating agents , IEEE Transactions on Systems, Man, and Cybernetics, Vol:26 , No:1, 1996. 9) Dr. M. L. Valarmathi, A.Meena Kowshalya, Improved Network Navigability and Service Search in Social Internet of Things (SIoT) , International Journal of Research and Scientific Innovation, Vol 3, No 11, pp: 75-77, 2015. 28 10) G. Danezis and P. Mittal. SybilInfer: Detecting Sybil Nodes using Social Networks. In NDSS, 2009 11) H. Yu , P. B. Gibbons , M. Kaminsky and F. Xiao SybilLimit: A near-optimal social network defense against sybil attacks , Proc. 2008 IEEE Symp. Security and Privacy, pp.3 -17 2008 82

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Journal of Applied Engineering Science 14(2016)1, 356

A. Meena Kowashalya - Detection of sibil s across communities over social internet of things

24) Usha Nandini Raghavan, Reka Albert, Soundar Kumara, Near linear time algorithm to detect community structures in large-scale networks , Physics Review E 76, 036106 (2007) 25) Valarmathi.M.L, Kowshalya.M, Aarthi.M, 2015 Research Challenges in the Social Internet of Things (SIoT) A Survey, Proceedings of National Conference on Science Research and Information Technology :128 133 26) W. W. Zachary, An information flow model for conflict and fission in small groups, Journal of Anthropological Research 33, 452-473 ,1977

Journal of Applied Engineering Science 14(2016)1, 356

27) Wei Wei ; Fengyuan Xu ; Tan, C.C. ; Qun Li, SybilDefender: Defend against sybil attacks in large social networks , Proceeding of IEEE InfoComm, PP: 1951 1959, March 2012. 28) Yan ,Lihua Yin, A Security Routing Mechanism against Sybil Attacks in Mobile Social Networks , APWeb Workshops,pp.325-332, Springer, 2014. Paper sent to revision: 05.02.2016. Paper ready for publication: 09.03.2016.

Original Scientific Paper

doi:10.5937/jaes14-10454

Paper number: 14(2016)1, 357, 84 - 92

COMBINATION OF PATCH AND WHEEL LOADS ANALYTICAL APPROACH TO PLATE BUCKLING Olga Miju kovi#* University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro Branislav "ori! University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Biljana #epanovi! University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro Past studies on the stability of rectangular plates under the influence of variable loads were based on assumptions of simplified stress distributions, which put the question of the accuracy of results thus obtained. The procedure of applying the exact stress functions in the problem of elastic stability of the plate with different boundary conditions under effects of patch and wheel loading is presented in this paper. Mathieu (1890) obtained the exact solution for the plane-strain state for a rectangular element for certain types of variable stresses on the boundaries. Baker at al (1993), following Mathieu s results, analyzed the general problem of a rectangular plate loaded by completely arbitrary distributions of (normal and/or shear) stresses along the edges of the plate. Analytical approach used for determination of the critical load is based on well known Ritz energy technique. The strain energy due to bending of the plate is defined in the traditional way. On the other hand, the exact stress distribution of Mathieu s theory of elasticity is introduced through the potential energy of the plate associated with the work done by external loads. Results for the critical load obtained by presented analytical approach are reaffirmed by numerical finite-element (FE) runs. Key words: Elastic stability of plates, Exact stress function, Patch and wheel load

INTRODUCTION In steel structures, buckling problem of the high steel girders under variable external loads is still very interesting topic. Presently available literature abounds with data regarding this problem, but mostly obtained by numerical or experimental methods. Analytical approach has been avoided mostly because of unknown stress distribution. In the series of papers based on Mathieu s method from 1890 [02], Pavlovi!, Baker and Tahan [08] and later Liu [05] and Miju kovi! [02] developed very precise approach for exact stress function determination for main case of rectangular plate under arbitrary external load. Existence of such solutions created the basis for the analysis of very complex stability problems in real steel structures. The case of patch and wheel loads can now be analyzed by using different mathematical models which are describing the mentioned problem with different

levels of accuracy. Considering models with different levels of complexity, it is possible to compare the results and analyze contribution of individual parameters to the value of the critical load. In this paper, the first, basic mathematical model is chosen to represent buckling problems of plates under combination of locally distributed compression and system of concentrated forces (Figure 1).

Figure 1: Basic model for patch-loading analysis

* University of Montenegro, Faculty of Civil Engineering, D ord a Va ingtona bb, 81000 Podgorica, Montenegro; olgam@ac.me

Olga Miju kovi - Combination of patch and wheel loads - analytical approach to plate buckling

The next step would be raising model to a more complex level through introduction of the shear stresses along vertical stiffeners with task to equilibrate external loads. The final goal would be defining and analyzing model with effects of shear stress at the flange-web junction whose distribution depends on the rigidity of the flange. Comparative analysis of the three models defining stability problem of rectangular plates with different boundary conditions under patch loading, can point to interesting conclusions about the relevance of various parameters and their influence on the value of the critical load. BASIC OUTLINE Analytical approach to stability problems of the plates due to the patch and wheel loading begins with determination of exact stress functions for selected model. In the series of papers [08-02] it has been already explained that any arbitrary load (normal and/or shear) which acts along the edges of the plate, can be described by the chosen functions (even and/or odd in relation to the coordinate axes), so the total solution is obtained by the adequate combination of eight basic cases (Figure 2).

In the Figure 3 the procedure for obtaining the exact stress distribution for the adopted model is explained by superposition of the adequate DEA and DEB solutions. The possibility to achieve exact stress functions for complex cases of plates under patch loading guarantees accurate analytical approach to critical load determination. So far, in the literature, only in the researches of Pavlovi! and Liu [01], it is possible to find analytical results for buckling loads, but exclusively for simply supported plates. Up to now, for this load case and the plates with different boundary conditions, there are no precise analytical solutions. Since the results for stress functions for the DEA and DEB cases can be found in literature [01-04] only Mathieu s basic approach will be presented in this paper. In his paper [02], Mathieu expressed the known equilibrium equations, without the presence of body forces, in terms of displacements:

¶s x ¶t xy + =0 ¶x ¶y ¶t yx ¶s y = 0 Mathieu + ¶y ¶x

Du = -

1 dn e dx

1 dn Þ Dv = e dy

(1)

Figure 2: Eight basic load cases

Figure 3: Basic model (DEA and DEB combination)

Journal of Applied Engineering Science 14(2016)1, 357

Olga Miju kovi! - Combination of patch and wheel loads - analytical approach to plate buckling

where: ! - Laplace s operator u, v displacements along the x i y directions respectively,

¶u ¶v - volumetric dilatation and + ¶x ¶y e = m / ( l + m ) - parameter related to Lame s

constants With the quite simple mathematical operations system (Eqs. (1)) can be transformed into the following form: (2) Dn = 0

Mathieu s approach to the 2D elasticity problem starts with the careful selection of two ordinary Fourier series for (Eq.(2)) with infinite unknown coefficients, taking into account the symmetry or anti-symmetry of the stresses with respect to the x and y directions. (3) n = n 1 +n 2 The following step presents the introduction of the function F (F1+F2), from the conditions that the equation is fulfilled: 1 1 1 DF = - n Þ DF1 = - n 1 i DF2 = - n 2 (4)

Finally, when displacements u i v are determined

dF dF (5) + a òn 1dx i v = + a òn 2 dy dx dy (l + 2 m ) a= where is constant expressed in m u=

terms of Lame s parameters, normal stresses N1 and N2 are defined along the x i y axes, as well as in-plane shear stress T3.

d 2F dx 2

(6a)

d 2F N 2 = ln + 2 man 2 + 2 m 2 dy

(6b)

ù é d 2F dn dn T3 = m ê 2 + a ò 1 dx + a ò 2 dy ú dx dy û ë dxdy

(6c)

N1 = ln + 2 man 1 + 2 m

ate general program (symbolic programming in the Mathematica) with implemented stress solutions for basic load cases (for original and rotate configuration LOAD, LOAD(ROT), Figure 2). Up to now, program contains general solutions for stress and displacement functions for six/twelve basic load cases (four/eight in self-equilibrium DEA(ROT), DOA(ROT), SOA(ROT) and SOB(ROT), and two/four that involve rigid-body translation DEB(ROT) and SEB(ROT)). The concept of computer program enables control of two highly important parameters that affects quality of solutions for stress functions. The first parameter is related to strict check of convergence and value stabilization of unknown coefficients in expressions for stresses while the second parameter determines necessary number of terms included in stress functions. More about mentioned parameters, as well as their influence on final stress value for some basic load cases can be found in literature [07-04]. In order to emphasize the quality of stress solutions, it has been decided to present one highly demanding load type - combination of patch load (" = 0.1) and concentrated forces (c = 0.5) (example in Table 1). Having in mind existence of girder reactions in form of concentrated forces, causing extreme stress concentration close to point supports, it was absolutely necessary to predefine identical stress contours in both cases analytical and numerical (ANSYS) solutions in order to enable adequate comparison of their position. Table 1: Stresses distributions within plate for the specific case of patch and wheel load combination obtained by analytical procedure and by software (ANSYS)

Analytical procedure for exact stress and displacement function determination is very complex and demanding. So, in order to enable stability analysis of plates under arbitrary external load, with possibility to vary dimensions and boundary conditions, it was absolutely necessary to cre86

Journal of Applied Engineering Science 14(2016)1, 357

Olga MijuÂ&#x161;kovi - Combination of patch and wheel loads - analytical approach to plate buckling

ANSYS (FEM)

Normal stress x Analytical solution

ANSYS (FEM)

Normal stress y Analytical solution

ANSYS (FEM)

Shear stress !xy Analytical solution

Journal of Applied Engineering Science 14(2016)1, 357

Overlap

Olga Miju kovi! - Combination of patch and wheel loads - analytical approach to plate buckling

Finally, analysis of diagrams in Table 1, especially in the third column presenting overlap of stress contours, shows that shapes and values of analytical and numerical solutions have high level of match. ANALYTICAL APPROACH TO PLATE BUCKLING The problem of the elastic stability of rectangular plates with different boundary conditions is investigated using the Ritz energy technique. The strain energy due to bending of the plate is defined in the traditional way. On the other hand, the exact stress distribution of Mathieu s theory of elasticity is introduced through the potential energy of the plate associated with the work done by external loads [05-04]. By adopting the exact stresses within a plate under patch and wheel loading and using the double Fourier series to represent any possible buckled profile, the buckling loads can

be obtained in a very accurate way. Analytical approach to plate buckling under patch and wheel loading is presented in the examples of the rectangular simply supported plates (SSSS) as well as in plates with two edges simply supported and other two clamped (CSCS). In order to verify the results from analytical method, the finite-element method (ANSYS) is used to produce buckling coefficients for the considered problem. Presently available literature has no records on analytical solutions dealing with the subject. The adopted deflection series In order to guarantee the accuracy, the double Fourier series are used to represent buckled profiles of the two chosen types of plates Eqs. (7) - (8). These series satisfy all boundary conditions, term by term, and, as it has been previously shown, are capable of representing any possible buckled profiles for very wide range of aspect ratios and load cases.

edges x = ± a/2 simply supported (S)

edges x = ± a/2 clamped (C)

edges y = ± b/2 simply supported (S)

Figure 4: Simply supported plate SSSS

Figure 5: Plate with mixed boundary conditions CSCS

(7) (8) Strain energy due to bending and work done by external loads During the evaluation of the total potential energy of the plate, the first step is defining the strain energy due plate bending in the traditional way.

The part of the potential energy of the plate associated with the work done by external loads is presented by the Eq. (10). In this expression, the stresses within the plate N1, N2 and T3 are given by Eqs. (6a) - (6c) that represent solutions of the Mathieu s exact approach. (9)

(10) 88

Journal of Applied Engineering Science 14(2016)1, 357

Olga Miju kovi! - Combination of patch and wheel loads - analytical approach to plate buckling

Introducing the exact stress functions for arbitrary type of external load makes the expression for the work done by external forces Eq. (10) more complex. It presents the basic difference in relation to the previous analyses of the stability of plates which are not simply supported along all edges. Formulation of eigenvalue problem Finally, after the definition of the strain energy of the plate bending U, and of the value which responds to the work done by external forces V, the total potential energy of the system can be written in form ! = U+V. From the minimum potential energy principle, the condition ! = U+V is given by

¶P ¶U ¶V = + ¶Wmn ¶Wmn ¶Wmn

(11)

which basically represents linear system of m n homogenous equations per unknown coefficients Wmn. The existence of nontrivial solution, expressed through condition that the determinant of the system is equal to zero, leads to the solution of the classical eigenvalue problem. In its scope, the lowest value has, for us, the only practical importance, which presents the requested critical load. Accuracy and quality of the second program part, related to the problems of plates stability, will be presented through analyzed case of patch and wheel load (from Table 1). In Table 2, for two types of boundary conditions (SSSS and CSCS), buckling coefficients are defined and appropriate buckling shapes are presented, in order to control the ability of chosen deflection functions to depict all buckling shapes. It may be concluded that critical load, as well as buckling shapes (Table 2) have a perfect match with numerical (ANSYS) solutions.

Table 2: Buckling shapes obtained by analytical procedure and by software (ANSYS) based on the finite element method (FEM)

Overlapping of analytical and numerical buckling shapes SSSS CSCS

Analytical solution K = 5.7672

Buckling load ANSYS Analytical solution K = 5.7661

discrepancy 0.02% Journal of Applied Engineering Science 14(2016)1, 357

K = 16.3867

ANSYS K = 16.3857

discrepancy 0.01% 89

Olga MijuÂ&#x161;kovi - Combination of patch and wheel loads - analytical approach to plate buckling

EXAMPLES AND RESULTS Examples proposed in this article are used not only as a way to prove precision of presented analytical approach but also to control behavior of the basic load types DEA and DEB in the cases of plates with different boundary conditions. Although, DEA and DEB loads are only two of eight fundamental cases (Figure 2), they are essential in the process of external load simulation. Namely, most of the real-life construction loads can be exactly described by appropriate superposition of several basic solutions, but patch compression and/or concentrated force (DEA and DEB) are almost inevitable part of each combination.

Chosen numerical examples are rather demanding and complex load cases shown in Figure 1. Two specific plate categories concerning boundary conditions (SSSS and CSCS), with plate aspect ratios ! = a/b = 0.5 and 1, under combination of patch loading with load length ratio " = 0.1-0.5 (" = l1/a, intensity # = 1) and wheel loads c = 0.10.5 (c =l2/a, intensity P= 0.1-0.5) were tested. Only few, chosen results are presented in Table 3 due to huge number of available data formed by combinations of various positions, intensities and characters of loads, as well as dimensions and boundary conditions of plates. Accuracy is guaranteed by quality of basic solutions.

Table 3: Buckling load for two plate types under various cases of patch and wheel load Results

Analytical solution %=0.5

Plate SSSS

(K=#tb /$ D) 2

! = 0.5

! = 0.4

! = 0.3

! = 0.2

! = 0.1

Plate CSCS

c = 0.1 c = 0.2 c = 0.3 c = 0.4 c = 0.5

c = 0.1

c = 0.2

c = 0.3

c = 0.4

c = 0.5

0.0

87.4985

254.9632

0.1

19.4285

20.0328

20.9511

22.1246

23.5053

51.5589

53.7950

57.1118

61.4004

66.4303

0.3

7.4809

7.7479

8.1521

8.6661

9.2651

19.8631

20.8441

22.2969

24.1716

26.3092

0.5

4.6323

4.8026

5.0608

5.3873

5.7672

12.3010

12.9258

13.8504

15.0416

16.3867

1.0

2.3731

2.4624

2.5974

2.7685

2.9666

6.3024

6.6295

7.1132

7.7354

8.4319

0.0

44.3406

130.0145

0.1

16.2432

16.6624

17.3026

18.1235

19.0935

43.1666

44.7151

47.0287

50.0249

53.5787

0.3

6.9557

7.1859

7.5353

7.9811

8.5035

18.4789

19.3245

20.5821

22.2117

24.1015

0.5

4.4253

4.5806

4.8157

5.1150

5.4642

11.7557

12.3249

13.1698

14.2620

15.5119

1.0

2.3176

2.4027

2.5314

2.6949

2.8847

6.1561

6.4678

6.9295

7.5247

8.1965

0.0

30.1776

89.1887

0.1

14.0546

14.3605

14.8299

15.4332

16.1468

37.4865

38.6104

40.3051

42.5073

45.1239

0.3

6.5241

6.7210

7.0253

7.4144

7.8719

17.3564

18.0873

19.1821

20.6058

22.2726

0.5

4.2454

4.3871

4.6023

4.8765

5.1975

11.2905

11.8096

12.5824

13.5845

14.7415

1.0

2.2673

2.3484

2.4712

2.6273

2.8090

6.0262

6.3230

6.7634

7.3324

7.9786

0.0

23.2385

69.3095

0.1

12.4882

12.7206

13.0753

13.5391

14.0846

33.4875

34.3413

35.6359

37.3210

39.3245

0.3

6.1635

6.3386

6.6054

6.9471

7.3496

16.4495

17.0917

18.0526

19.3029

20.7734

0.5

4.0910

4.2209

4.4182

4.6700

4.9652

10.9009

11.3768

12.0859

13.0060

14.0735

1.0

2.2225

2.2999

2.4171

2.5662

2.7399

5.9135

6.1968

6.6172

7.1606

7.7801

0.0

19.1729

57.7698

0.1

11.3311

11.5135

11.7950

12.1581

12.5883

30.5891

31.2662

32.2923

33.6250

35.2091

0.3

5.8699

6.0246

6.2606

6.5627

6.9187

15.7255

16.2968

17.1498

18.2557

19.5552

0.5

3.9599

4.0795

4.2611

4.4928

4.7647

10.5794

11.0195

11.6740

12.5208

13.5033

1.0

2.1834

2.2573

2.3693

2.5117

2.6777

5.5180

6.0894

6.4917

7.0108

7.6028

Journal of Applied Engineering Science 14(2016)1, 357

Olga Miju kovi! - Combination of patch and wheel loads - analytical approach to plate buckling

Results

Analytical solution #=0.5 Plate SSSS

(K=!tb /" D) 2

= 0.5

= 0.4

= 0.3

= 0.2

= 0.1

Plate CSCS

c = 0.1 c = 0.2 c = 0.3

c = 0.4 c = 0.5

c = 0.1

c = 0.2

c = 0.3

c = 0.4

c = 0.5

0.0

29.4925

57.3550

0.1

9.9230

10.3208

10.9536

11.8073

12.8608

19.2635

19.8512

20.7400

21.8947

23.2558

0.3

4.2640

4.4839

4.8395

5.3343

5.9727

8.2731

8.5933

9.0835

9.7365

10.5283

0.5

2.7154

2.8640

3.2052

3.4437

3.8855

5.2677

5.4831

5.8139

6.2574

6.7988

1.0

1.4232

1.5048

1.6377

1.8256

2.0731

2.7606

2.8785

3.0599

3.3045

3.6047

0.0

15.0502

29.1458

0.1

7.5009

7.7248

8.0773

8.5414

9.0934

14.5368

14.8656

15.3647

16.0028

16.7370

0.3

3.7444

3.0128

4.1831

4.5535

5.0203

7.2593

7.5042

2.9104

8.3741

8.9658

0.5

2.4949

2.6198

2.8214

3.1013

3.4608

4.8375

5.0185

5.2964

5.6665

6.1141

1.0

1.3602

1.4345

1.5553

1.7249

1.9463

2.6377

2.7451

7.8793

3.1232

3.4036

0.0

10.3563

19.9023

0.1

6.1201

6.2649

6.4924

6.7887

7.1350

11.8055

12.0140

12.3336

12.7420

13.2074

0.3

3.3656

3.4994

3.7134

4.0037

4.3638

6.5081

6.7006

6.9970

7.3867

7.8486

0.5

2.3209

2.4277

2.5997

2.8365

3.1369

4.4921

4.6458

4.8825

5.1970

5.5749

1.0

1.3068

1.3750

1.4855

1.6399

1.8400

2.5315

2.6297

2.7809

2.9837

3.2304

0.0

8.0916

15.3852

0.1

5.2544

5.3575

5.5194

5.7295

5.9732

10.0596

10.2046

10.4284

10.7153

11.0418

0.3

3.0869

3.1969

3.3725

3.6092

3.8997

5.9413

6.0975

6.3386

6.6553

7.0290

0.5

2.1851

2.2781

2.4277

2.6326

2.8901

4.1249

4.3476

4.5524

4.8239

5.1490

1.0

1.2627

1.3257

1.4277

1.5696

1.7525

2.4412

2.5314

2.6705

2.8568

3.0829

0.0

6.7933

12.7487

0.1

4.6781

4.7570

4.8809

5.0414

5.2269

8.8672

8.9757

9.1435

9.3588

9.6039

0.3

2.8799

2.9734

3.1223

3.3220

3.5652

5.5063

5.6371

5.8391

6.1035

6.4147

0.5

2.0797

2.1624

2.2952

2.4761

2.8019

3.9918

4.1085

4.2887

4.5269

4.8111

1.0

1.2269

1.2857

1.3807

1.5125

1.6814

2.3649

2.4485

2.5775

2.7498

2.9585

In case of simply supported plate (Table 3), extremely good behavior of analytical model is confirmed. Maximal discrepancy from numerical (FEM) solution is less than 0.3%. On the other side, load action over clamped edge (Table 3), leads to slightly higher differences (max 0.5%), but still proving good capability of deflection functions to adequately simulate buckling shapes even in these specific plate types. All of these examples are highly demanding in each aspect of presented analytical approach. Stress functions have to describe precisely very complex stress distribution within plate under patch load and system of concentrated forces, while deflection functions have to be capable of providing ideal buckling shape for all load combinations (Table 2). Hence, it has been proved that adopted deflection functions and defined stress functions, for the analyzed cases of plates with mixed boundary conditions, subjected to patch and wheel loads (DEA and DEB) are capable to produce Journal of Applied Engineering Science 14(2016)1, 357

highly accurate solutions. Finally, it may be concluded that shown procedure presents rare analytical approach to stability problems of plates with different boundary conditions which satisfies very demanding criteria of accuracy and applicability in rather complex cases of external load. REFERENCES 1) Baker G., Pavlovi& M. N., Tahan N. (1993): An exact solution to the two-dimensional elasticity problem with rectangular boundaries under arbitrary edge forces , Phil. Trans. R. Soc. London, A 393, pp. 307-336 2) Liu Y. G. (2006): Buckling of Plates under Non-Uniform Stresses, with Particular Emphasis on Shear , Ph. D Thesis, Imperial College, London 3) Mathieu E. (1890): Theorie de l elasticite des corps solides , Seconde partie. Gauthier Villars, Paris 91

Olga Miju kovi! - Combination of patch and wheel loads - analytical approach to plate buckling

4) Miju kovi! O. (2008): Analiza stabilnosti pravougaonih plo"a kori !enjem ta"ne funkcije napona , Doktorska disertacija, Gra#evinski fakultet Univerziteta u Beogradu, Beograd 5) Miju kovi! O., $ori! B. (2013): Patch loading analytical approach to critical load determination , original scientific paper, Gra#evinar, Journal of the Croatian Association of Civil Engineers, 65(1), pp. 1-10 6) Miju kovi! O., $ori! B., !epanovi! B. (2014): Exact stress functions implementation in stability analysis of plates with different boundary conditions under uniaxial and biaxial compression , Thin-Walled Structures, 80, pp. 192-206

7) Miju kovi! O., $ori! B., !epanovi! B. (2015): Accurate buckling loads of plates with different boundary conditions under arbitrary edge compression , International Journal of Mechanical Sciences, 101-102, pp.309-323 8) Miju kovi! O., $ori! B., !epanovi! B., ugi! Lj. (2016): Analytical model for buckling analysis of the plates under patch and concentrated loads , Thin-Walled Structures, 101, pp.26-42 Paper sent to revision: 05.02.2016. Paper ready for publication: 15.03.2016.

Journal of Applied Engineering Science 14(2016)1, 357

Original Scientific Paper

doi:10.5937/jaes14-10469

Paper number: 14(2016)1, 358, 93 - 101

DESIGNING ENERGY EFFICIENCY GLAZED STRUCTURES WITH COMFORTABLE MICROCLIMATE IN NORTHERN REGION Viktor Pukhkal St. Petersburg State University of Architecture and Civil Engineering, St. Petersburg, Russia Andrii Bieliatynskyi National Aviation University, Kyiv, Ukraine Vera Murgul St. Petersburg State Polytechnical University, St. Petersburg, Russia With the rising demand for entirely glass facades and glass roofs, the need to carry out an additional analysis of conditions to secure comfortable microclimate has appeared. There is a peculiar issue to work out design principles of glass buildings in the northern regions. The article deals with the general data of inside temperature in rooms and on internal glass surface of commercial pavilions made of glass. The data to work out the design of glazing for considerable areas of glass facades and glass roofs in the northern regions have been given herein. The factors, which make it uncomfortable for people to stay inside glass space, have been researched. Heat losses in commercial pavilions with various dimension ratios and the amount of energy consumed for heating have been determined in the case of the weather conditions in the northern city of Saint-Petersburg (Russia). Keywords: Translucent structures, Energy efficiency, Building, Glass, Construction INTRODUCTION Facades made of glass are very popular nowadays. They look stylishly and perfectly suit the modern architecture of the cities, and lightweight prefabricated structures with glass fillings provide quick installation [16]. Most of conducted researches of glazed buildings relate to the problem of overheating and passive usage of solar heat [09-10]. A great number of researches are devoted to the correlation between geometry shape of glazed buildings and their energy efficiency characteristics [15-02]. Insufficient attention is paid to the problem of applying glazed external structures in northern regions. Popularity of glass buildings demanded an additional analysis of comfortable microclimate provision problem in them. The necessity of generalization and systematization of methodologies for a comfortable human residence appeared for buildings which have significant areas of facade or roof glazing in the northern regions. Glass surfaces are the most problem areas of external structures due to high thermal losses in the winter period. Thus, developing methods of improving their thermal insulating properties is becoming actual [17].

Another issue to be taken into account when designing glass structures is related to the low temperature values of interior glass surfaces in the winter periods of the year if to compare with the temperature values of the elements of other building envelope surfaces thereby resulting in uncomfortable conditions for people in the area close to windows. According to the survey results the majority of people working in office facilities with the facades made of glass or living in flats with panoramic windows feel uncomfortable to a significant extent in cold seasons due to a feeling of Â&#x2018;exposure to coldÂ&#x2019; coming from glass windows in winter time [08]. This issue with the reference to commercial pavilions based on glass structures will appear to be more crucial as almost all the envelopes have lower temperature values. MATERIALS AND METHODS Temperature and humidity requirements for glass buildings On the basis of the analysis performed to evaluate usage and maintenance conditions of the build-

* St. Petersburg State University of Architecture and Civil Engineering, 2-Krasnoarmejskaja, Saint-Petersburg, 190005, Russia , 357 pva1111@rambler.ru

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

ings with considerable areas of glass facades and glass roofs, heat losses in buildings and the amount of energy consumed for heating of pavilions with various dimension ratios have been determined using the computational method. Exhibition and commercial pavilions based on glass structures were taken for consideration (Figure 1). Internal air parameters are standardized only for work area of a room. Work area is the area in a room confined between two planes, which are parallel to the walls and a floor: at the heights of 0.1 and 2.0 m above floor level (no closer than 1 m from a ceiling in case of ceiling heating), at the distance of 0.5 m to be measured from internal surfaces of interior and external walls, windows and heaters (Figure 2). The comfort of the microclimate in glazed buildings in winter period is defined by the regulations of heat exchange between human body and an internal environment of the room and glazed external structures [12]. a)

Figure 2: Work area in a room

There are the following standards for interior climate parameters in rooms [10]: - internal air temperature, tint, °!; - resultant temperature, tres, °!; - relative humidity of internal air, !int, %; - air velocity in a room, Wint, m/". Two parameters air temperature and temperature of the surfaces around a room are exposed to achieve comfortable temperature in the systems assigned for heating. The combination of the temperatures of the surface around a room and air form the resultant temperature which is to be determined as follows:

tres =

tint + t R °! 2

(1)

where tR - radiant temperature of a room (average temperature of the surfaces in a room), °!; - at the air velocity starting from 0.2 up to 0.6 m/s.

tres = 0.6tint + 0.4t R °! b)

Figure 1: a) Exhibition pavilion (Slovenia), b) Botanic garden Biosphere (Italy)

(2)

The values of the optimal resultant temperature in the cold period of the year are the following - 18 20 °C above zero. Glazing surfaces in a room will be determinant for comfortable conditions in winter time. When the temperature of the internal glass goes down up to 10 °! human heat losses due to the radiation towards usual windows of an ordinary building may reach the values 5 times more than a lower boundary point of heat or cold that a person can feel [08]. Consequently, this effect will increase with the increase of external glazing area in a building with totally glazed facades. An average temperature of internal surfaces of translucent structures depends on a heat release Journal of Applied Engineering Science 14(2016)1, 358

Viktor!Pukhkal-!Designing!energy!efficiency!glazed!structures!with comfortable!microclimate!in!northern!region

rate of an internal glazing surface and thermal resistance.

from the room s side is determined under the following formula:

t int = tint -

t intb = tint -

tint - text U a int

(3)

where int - average temperature of an internal glazing surface, °!; tint- air temperature in a room, °!; text- external air temperature, °!; "int- heat release rate of an internal surface of an envelope, W/(m2 °!); U - heat transfer factor of a translucent structure, W/(m2 °!). Calculation results regarding the temperatures of an internal glazing surface in relation to various values of a heat transfer factor for windows and external temperature values having temperature in a room equal to 20 °!, are given in the Table 1. The calculations have been made for the central area of a glass unit with a boundary area excluded. When making thermotechnical calculations for translucent structures it is necessary to consider thermal resistance in a relation area of a glass unit and non-uniformity of their temperature fields. The temperature of the surfaces of boundary areas in regard to the glass unit (at the distance up to 200 mm from a spacer frame)

tint - text U a int kÄ

(4)

where k - the factor which considers changes of values U and at different points of the vertical and horizontal sections of the glass unit boundaries, and is to be determined according to the Table 2. For instance, the calculation results for the relation (4) in regard to the temperature of the surface of the double-glazed window having a wooden sash with due account for boundaries are presented in the Figure 4. The following values are assumed: "int=8.7 W/(m2 °!); tint=20 °!; teet= -10°!; U=2.0 W/(m2°!); the glass unit dimensions - 3000#3000 mm. The data obtained accurately coincide with the data given in the article [03] and defined in accordance with the results of the thermal imaging made for internal surfaces of glass units. The temperature of the surface in the boundary area of a glass unit changes with due account for a type of a spacer frame and a glass unit configuration [05]. The values of the temperature in boundary areas of the glass units in accordance with the different types of spacer frames [11] are shown in the Table 3 and in the Figure 5.

Table!1.!Temperature!of!an!internal!glazing!surface!to!external!air!temperature!relation External air temperature, °!

Temperature of an internal glazing surface in relation to a heat transfer factor of a glass structure,°! 0,3

0,4

0,5

1,0

2,0

2,5

19.3

19.1

18.9

17.7

15.4

13.1

-10

19.0

18.6

18.3

16.6

13.1

9.7

-20

18.6

18.2

17.7

15.4

10.8

6.2

-30

18.3

17.7

17.1

14.3

8.5

2.8

Table!2.!The!factor!k !!which!considers!the!temperatures!of!the!boundary!areas!of!the!glass!units Configuration and material of a window sash

Wood

Aluminum

Section along the glass unit

Factor k the glass unit at the destination starting from a spacer frame, [mm] 5

100

150

200

Upper vertical

1.05

1.2

1.26

1.16

1.06

1.02

Lower vertical

0.62

0.72

0.82

0.91

0.96

0.98

Horizontal

0.75

0.87

0.95

0.98

0.99

1.00

Upper vertical

0.93

1.09

1.21

1.14

1.05

1.02

Lower vertical

0.59

0.7

0.81

0.90

0.95

0.98

Horizontal

0.67

0.84

0.94

0.97

0.99

1.00

Journal of Applied Engineering Science 14(2016)1, 358

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

Table 3. Surface temperature in boundary areas of the glass units with different spacer frames at the temperature internal air 20 째! above zero Surface temperature in boundary areas of the glass units,[째!] External air temperature, [째!]

0 -10 -20 -30

one-chamber glass

Double-glazed

AL*

RST*

SWS*

RST

SWS

11.0

11.9

13.3

11.5

12.2

13.8

6.7

7.7

10.0

7.2

8.3

10.8

2.3

3.6

6.6

3.0

4.4

7.5

-2.2

-0.4

3.2

-1.3

0.5

4.4

Note: Data given for the glass units with the aluminum spacer frames. Figure 4: Internal surface temperature fields for the double-glazed widow with a wooden sash (X- distance form a lower or a side spacer frame of the glass unit, mm)

Figure 5: Surface temperature in boundary areas of the glass units with different spacer frames at the internal air temperature 20 째! above zero

Journal of Applied Engineering Science 14(2016)1, 358

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

The following should be considered when designing translucent structures: - the value of a heat transfer factor of a glass unit is given for the central area of a vertical glass unit in the specifications stated by a manufacturer; - the value of a heat transfer factor for the glass unit boundaries in accordance with the type of a space frame used is 0.1 0.3 W/(m2 °!) more than for the central area. Depending on the configurations and dimensions of the glass units the boundary area accounts for nearly 2 - 4% out of total area of a translucent structure; - the value of a heat transfer factor of the glass unit profile system usually is within the limits of 1 1.5 W/(m2 °!), and its share in a total area of a translucent structure also depends on the dimensions and the configuration of the cells and amounts to 2 - 4% ; - the value of a heat transfer factor of the glass units placed horizontally or at an angle of, "20° is significantly higher than the one for the vertically placed glass units nearly 30 - 70% [11]. Lower temperature of internal surface of glazing comparing to average temperature in the room leads to 3 effects which create discomfort: 1. Cold air flow near the glazing. Cold air flow which appears on the glass surface lowers from the window and spreads around the floor. 2. Radiation heat transfer between human and external glass structures. Cold surface of the window leads to the unpleasant cooling of human body. 3. Formation of the condensate on the internal surface of the glazing. During the cooling of air layer which adjoins the glazing, it s temperature can become lower than the dew point, which leads to the condensate appearing on the internal surface of the building. Mentioned effects could be prevented with certain actions or at least their impact can be reduced RESULTS AND DISCUSSION Cold air flow near the glazing Temperature comfort in the working space depends on speed of air flow. The calculated air speed, substantiated by the action of a pulldown flow near the window should not exceed Journal of Applied Engineering Science 14(2016)1, 358

the standard values. The maximum value of the air current velocity which emerges near an envelope due to free convection and goes along the floor of the room is determined by the following relation [06]

wmax

æb ö = 3.33w0 ç 0 ÷ è l ø

0.5

(5)

where w0- average velocity in initial section of an air current along the area (near an envelope), m/s; b0- width of an air current in initial section, m; l - distance from an envelope, m. Average velocity in initial section of an air current along the area

w0 = 0.061( tint - t int ) H 0.5 0. 5

(6)

where H - height of glazing, m. Width of an air current in initial section

b0 = 0.071( tint - t int )

-0.167

H 0.5

(7)

Calculation results for the maximum value of the air current velocity at the distance of 0,5 m from the envelope in accordance with the relations (3) (5) are given in the Figure 6. For instance, the temperature of the internal glazing surface for a double-glazed unit with the heat transfer factor equal to 2 W/(m2 °!) and the external air temperature 10 °! below zero, accounts for 13.1 °!. Then, with tint - !int=20-13.1=6.9 and the glazing unit height H=3m the maximum air current at the distance of 0.5 m form the envelope will be equal to 0.39 m/s. The optimal air velocity no more than 0.2 m/s; and the accessible one no more than 0.3 m/s [01]. Consequently, it is necessary to take into account all the measures required for to safeguard the work area of the room against the cold air flow. It should be noted that there are a lot of relations with varied velocity values which can be used to calculate the maximum air current velocity which emerges near the envelope due to free convection and goes along the floor in the room. According to the article [08] the following relation for the distance from the envelope within the limits of 0.4 - 2 m is given herein:

wmax

(t -t ) = 0.095 int int 2

0 ,5

H 0 ,5

(8)

l + 1.32 97

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

resulting in the velocity value equal to wmax=0.24 !/". This divergence can be explained by the difference in the relation calculation approaches and accuracy in experimental research data. According to the authors the calculations should be made in compliance with the relations (5) (7) that

ensures better climate conditions in the work room. The air flow velocity near the windows exceeds the one required under sanitary and hygienic requirements by 2 times. It would be rational to install the heaters under the windows.

Figure 6: Relation of the maximum air current velocity at the distance of 0.5 m of the envelope to the temperature difference between internal air and air in the area of glazing surface and to height of glazing units

Radiation heat transfer between human and external glass structures Human heat losses caused by radiation can be determined by a temperature of an internal glazing surface, dimensions of the glazing and a person s position in relation to light openings. Accessible internal glazing surfaces temperatures are determined by the relation [06]:

t int .p = 14 -

3 .5 °# fh - w

(9)

where !h-w - the factor of heat radiation emitted from human skin on the glazing surface. Heat radiation factor is [19]

fh - w = 1 -

0.8 Fw 0.5

where Fw - glazing area, m2. 98

(10)

Exhibition halls are normally five-sided glazing systems (only floor is not glazed). For this reason the value of a heat radiation factor can be assumed to be roughly equal to 1 ( !h-w= 1 ). Then the temperature of internal surfaces is equal to "int.p=14-3.5=10.5 °#. According to the relation (1) it is possible to find out that the value of the heat radiation factor with the estimated temperature of the external air equal to 20 °# below zero will amount to 2.07 W/(m2 °#), and correspondingly with the temperature equal to 30 °# below zero 1.65 W/(m2 °#). Human skin heat radiation emitted on cold glazing surfaces can be balanced with warm surfaces located at or under cold surfaces. Formation of the condensate on the internal surface of glazing Moisture condensation occurs in a boundary layer which is right at an envelope s surface. Journal of Applied Engineering Science 14(2016)1, 358

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

Dew point temperature of the air in the room at the temperature of 20 °! above zero with the relative humidity 50% accounts for 9.3 °!. If to compare glazing surface temperatures (Table 1) with the dew point temperature one may find out that there is a low risk of condensation in the central area under these conditions when using gazed units with the low heat transfer rate since the temperature of glazing is higher than the dew point temperature. Owing to the lower temperature of the glazed units boundaries condensation quite often occurs in the area of boundaries. There is risk of condensation in case of one-chamber glass units with the aluminum spacer frames when the temperature of the external air is lower than 3 °C below zero. And there is risk of condensation in case of double-glazed units with the composite frames when the temperature of the external air is equal to or lower than 13.5 °C. The temperature of boundaries may be changed if another type of a spacer frame is used and if the window frame profiles are changed. When designing vertical or horizontal surfaces at an angle to the horizon, glass heat radiation towards sky should be taken into account as it can cause condensation or ice formation (in most cases at nights). In this case it is suggested that an external glass with a low emission rate and with a rigid surface faced outward and, not inward - (as it is normally accepted in standard options) should be applied [08]. Condensation may be avoided if cooling of the air is prevented up to the dew point temperature owing to the warm air, or the dew point temperature is changed due to the drier air move to the glazing surfaces. Heat losses of commercial halls based on glass structures The parameters of thermal and humidity conditions in could time of a room are determined by heat capacity of a heating system and thermal insulation parameters of building envelopes (in general cases exterior walls with one or more windows) [04]. Let s consider heat losses of an commercial hall due to heat transfer through glazing envelope structures (coating and exterior walls) of an exhibition hall with regard to the environment conditions in case of Saint-Petersburg: Journal of Applied Engineering Science 14(2016)1, 358

- internal air temperature - tint = 18 °!; - external air temperature - text = -24 °!. When making computations extra heat losses, which are related to building envelopes orientation and external infiltrating air heating, are taken into account. The exhibition hall is made of translucent structures Qbiss Air [07] shown in the Figure 1. The glass modular façade system «Qbiss Air» is the multilayer insulation façade system with the following parameters: - the heat transfer factor of the structural module with seven layers - U = 0.19 W/(m2 °!); - the heat transfer factor of the translucent structure (including boundaries, profile systems and horizontal systems) U = 0.27 0.45 W/(m2 °!); - an assumed heat transfer factor for the facade glazing U=0.4 W/(m2 °!); - an assumed heat transfer factor for the roof glazing U=0.32 W/(m2 °!). Heat losses through building envelopes can be determined according to the following relation n

Q = å Fi × (tint - text ) × U i ,

(11)

i =1

where Fint - an estimated area of the envelope i , m2. Calculation results related to heat losses through building envelopes with the dependence on the pavilion s volume and the ratio of total envelopes area (F, m2) to the pavilion s volume (V, m3) are shown in Figure 7. A specific annual consumption of heat energy meant for heating per 1 m2 of the floor area of the pavilion is specified in Fig. 8. When calculating specific energy consumption a 12-hours daily work is taken. Heating system operates at nights with reduced energy consumption and ensures the temperature of the internal air equal to 5 °! ( background heating ).

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

Figure 7: Heat losses in an commercial hall.

Figure 8: Specific annual consumption of heat energy for heating

100

Journal of Applied Engineering Science 14(2016)1, 358

Viktor Pukhkal- Designing energy efficiency glazed structures with comfortable microclimate in northern region

CONCLUSION 1. Data about the temperature regime indoors and at the internal surface of the glazing was generalized for the exhibition and trade pavilions made of glass. 2. Information for designing of glazing is exposed, considering winter conditions of building exploitation, which have significant areas of facade or roof glazing 3. Factors which create the discomfort among the people in a room with a large glazed area were analyzed: - the flow of a cold air which appears on the cold surface of the window and goes down spreading around the floor - human radiation heat transfer with the external glass structures; - formation of the condensate on the internal surface of glazing 4. Heat losses of exhibition pavilions with different ration of sizes and energy consumption of heating systems for Saint-Petersburg (Russia). REFERENCES 1) Babiak, J., Olesen, B.W., Petrá , D. (2013): Low Temperature Heating and High Temperature Cooling Embedded. Water Based Surface Heating and Cooling Systems, Guidebook 7, REHVA. 2) Boriskinoj, I.V. (2012): Buildings and structures with translucent facades and roofs. Theoretical bases of designing of glass constructions, St. Petersburg: Stroyizdat. 3) Garber-Slaght, R., Craven, C. (2012): Evaluating window insulation for cold climates. Journal of Green Building, 7, p. 32. 4) GOST 30494-2011. Residential and public buildings. Options indoor climate, Moscow, Publisher: Standartinform, 12 p. 5) Guidelines for the calculation of translucent constructions of buildings (2006) NIISF. Moscow: Strojizdat. 6) http://www.trimo.si/media/qbiss-air-brochure-en_ 23006.pdf (retrieved on November 7th, 2015). 7) Huang, Y., Niu, J. (2015): Application of super-insulating translucent silica aerogel glazing system on commercial building envelope Impact on space cooling load, Energy, 83, pp. 316-325. Journal of Applied Engineering Science 14(2016)1, 358

8) Karlsson, J. (2001): Windows Optical Performance and Energy Efficiency, Uppsala: Tryck & Medier, SE, 57 p. 9) Korniyenko S.V. (2011): The estimation of enclosing structures edge zones influence on thermal performance and energy efficiency of buildings, Magazine of Civil Engineering, 8 (26), pp. 5-12. 10) Leskovar, V. ., Premrov, M. (2011): An approach in architectural design of energy-efficient timber buildings with a focus on the optimal glazing size in the south-oriented façade, Energy and Buildings, 43 (12), pp. 3410-3418. 11) Majorov V.A. (2014): The transfer of heat through the windows: Textbook, Moscow: Publisher ACB. 12) Mihalakakou, B. (2002): On the use of sunspace for space heating/cooling in Europe, Renewable Energy, 26, p. 415. 13) Parasonis, J, Keizikas, A and Kalibatiene, D. (2012): The relationship between the shape of a building and its energy performance, Architectural Engineering and Design Management, 8(4), pp. 246-256. 14) Parasonis, J., Keizikas, A. (2013): Increasing Energy Efficiency of the Translucent Enclosure Walls of a Building, Procedia Engineering, Vol. 57, pp. 869-875. 15) Parasonis, J., Keizikas, A., Endriukaityt, A., Kalibatien, D. (2012): Architectural solutions to increase energy efficiency of buildings, Journal of Civil Engineering and Management, 18, pp. 1-11. 16) Saukko T., Lejnonen L., Zuevskij K. Multifunctional glass electrically heated (2013) High-rise buildings, 5, pp. 90 95. 17) Wall, M. (1997): Distribution of solar radiation in glazed spaces and adjacent buildings. A comparison of simulation programs, Energy and Buildings, 26, p. 129. 18) egarac Leskovar, V., Premrov, M. (2012): Design approach for the optimal model of an energyefficient timber building with enlarged glazing surface on the south façade, Journal of Asian architecture and building engineering, vol. 11, no. 1, pp. 71-78. Paper sent to revision: 01.02.2016. Paper ready for publication: 15.03.2016.

101

Original Scientific Paper

doi:10.5937/jaes14-10470

Paper number: 14(2016)1, 359, 102 - 108

ANALYTICAL SOLUTION FOR SIMPLY SUPPORTED LAMINATED COMPOSITE PLATES BASED ON PARTIAL LAYERWISE THEORY Marina Rako!evi" University of Montenegro, Faculty of Civil Engineering, Montenegro Anisotropic composition of layered composite plates requires more accurate mathematical and calculation models. By applying Reddy s layerwise theory we can cover a wide range of problems of layered composite plates with arbitrary arrangement of layers through the plate thickness. The analytical method of solving bending equations in Layerwise Theory is based on the assumed displacement field in the form of the double trigonometric Fourier s series. The analytical solution can be used as a test solution for solutions obtained by using numerical methods, including finite element method. For Partial Layerwise Theory, the paper presents the equations of bending for laminated composite plates and the algorithm for calculation of deflections and stresses in an arbitrary cross section of a simply supported rectangular plate loaded with distributed load. On the basis of the algorithm presented in this paper, author has prepared Fortran program called ANSLACOP (ANalytical SOlution of LAminated COmposite Plates), whose structure will be presented in the paper. It is presented that the solution obtained by using this program very quickly converges depending on the adopted number of members of double trigonometric series. Key words: Laminated composite plate, Layer, Bending, Partial Layerwise theory, Analytical solution

INTRODUCTION Layered composite plates, with layers carrying in different directions in the plane plate, wherein each of the layers contains parallel fibers of a material in the basic of the other material that carry only in one direction, show extremely anisotropic behavior. For more accurate determination of the stress-strain components it is necessery to use theories which conduct analysis at the level of layer or the level of fiber/basic compaund. Theoretical analysis of the layered composite plates can be conducted using the Equivalent Single Layer Theory (ESLT) and the Layerwise Theory [02],[01],[08]. ESLT treates layered composite plate as static equivalent to a single layer. Single-classical theories include classical theorie and shear theory of the first, second and higher order. The simplest ESLT is the Classical Laminated Plate Theory (CLPT), which is based on the application of Kirchoff s theory of plates. This theory is

applied for the calculation of thin homogeneous plate. For moderatelly thick and thick plates with a high degree of anisotropy, a solution obtained by applying this theory is not satisfactory accurate because the calculation does not introduce deformation caused by shear. The next onelayer theory is the First-Order Shear Deformation Theory (FSDT) that resulted from the limited CLPT. FSDT introduces a constant sliding across the plate thickness. Higher order shear theory (Second-Order Plate Theory, Third-Order Plate Theory) constant shear through the thickness of the plate is replaceing by shear assumed in the form of higher order polynomial (quadratic, cubic). For theoretical analysis of thick and moderately thick laminated composite plates layerwise theories are applied including the Generalized Layerwise Plate Theory (GLPT). In the GLPT considerations are implemented at the level of the layer, and depending on the adopted assumptions, the Partial Layerwise Theory and

*Faculty of Civil Engineering, University of Montenegro, Cetinjski put bb, 81000 Podgorica, Montenegro; marinara@ac.me

102

Marina Rako!evi - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

Full Layerwise Theory stand out. In the Partial Layerwise Theory is assumed that componental displacement perpendicular to the plane of the plate is constant through the thickness of the plate, w=const. Follows that it is the componental displacement of w function two coordinates x and y. In this theory componental displacements in the plane plate, u and v, can be obtained by superpositioning appropriate displacements defined in the medium plane plate, which are a function of the coordinates in the plane (x, y), and added displacements defined as the product of nodal displacements and one-dimensional interpolation functions assigned to the function of coordinate z at the thickness of the plate [01], [08]. In the Full Layerwise Theory is assumed to be componental displacements functions of all three coordinates x, y and z for which the mathematical model of this theory is much more complex than a mathematical model defined in the Partial Layerwise Theory. Depending on the required accuracy and efficiency in stress deformation analysis of laminated composite plates the selection of the theory that will be used is made. If dealing with a thin layered composite panels it is most economical to apply ESLT, as for thick and moderately thick plates, and depending on the required accuracy and efficiency, Layerwise Theories are recommended. After assumed displacement field of chosen theory it is necessary to define the connections of displacements and deformations, and after the connection of deformations and stresses, depending on the adopted physical and mechanical characteristics of the material, all within the observed coordinate system (x, y, z). By applying the principle of virtual displacements the corresponding equations of adopted theory are obtained [02], [01]. The equations of the theory can be solved analytically or numerically [05]. Analytical solutions are sought in the form of trigonometric functions that define the primary variable of the relevant theory. In addition to closed solutions, numerical solutions can be obtained by applying numerical methods, such as finite element method. Numerical solutions of primary variables are obtained for a pre-defined points of the layered composite plate in the plane and in the thickness of the plate depending on the adopted mathematical model. In the analysis of the accuracy of numeriJournal of Applied Engineering Science 14(2016)1

cal solutions, analytical solutions can be used as test solutions. In this paper is presented an algorithm of FortranÂ&#x2019;s program ANLACOP which produces analytical solution to equation of the problem of bending simply supported laminated composite plates based on the assumptions of the Partial Layerwise Theory. Also, this paper is presented an analysis of convergence of results and comparison with existing results. MATEMATICAL MODEL OF THE PARTIAL LAYERWISE THEORY Reviews are carried out in the Cartesian coordinate system (x, y, z), assuming that the layered composite plate comprises layers which are arbitrarily oriented in the plane of the plate (x, y). Each of the layers contains parallel fibers that carry only in one direction. In Partial Layerwise Theory it is assumed that the componental displacements of the arbitrary point of layered plate containing N orthotropic layers, [05]and [06], are defined by:

u ( x , y , z ) = u ( x, y ) + U ( x, y , z )

(1)

v ( x, y , z ) = v ( x , y ) + V ( x, y , z ) w( x, y, z ) = w( x, y )

where u(x,y), v(x,y), w(x,y) are displacements of the middle plane of the plate, while U(x,y,z), V(x,y,z) are additional displacements through the plate thickness defined by following formulations: n

U ( x, y, z ) = ĂĽ u J ( x, y )y J ( z )

(2)

J =1 n

V ( x, y, z ) = ĂĽ v J ( x, y )y J ( z ) J =1

In the previous relation uj, vj are the nodal displacements across the plate thickness, !j(z) are continuous, general one-dimensional interpolation functions are defined by the thickness of the plate, and n is number of nodes per plate thickness, Figure 1. By applying the principle of virtual displacements the constitutive equations of the theory of bending of layered plates are formed, [05], [07] and [06]:

N x , x + N xy , y = 0 N xy , x + N y , y = 0 Qx , x + Qy , y + q = 0

N xj, x + N xyj , y - Qxj = 0 N

j xy , x

j y, y

(3)

j y

-Q = 0 103

Marina Rako!evi - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

Figure 1: Displacement through the thickness of the plate

where:

(N , N x

h/ 2

, N xy ) =

ò (s

, s y , s xy )dz

-h/2 h/2

( Q , Q ) = ò (s x

, s yz ) dz

-h/ 2

( N xJ , N yJ , N xyJ ) =

h/2

ò (s

, s y , s xy )y J ( z ) dz

-h/ 2

J x

, QyJ ) =

h/2

ò (s

, s yz )y , Jz dz

(4)

-h/ 2

(!x, !y. !xy, !xz, !yz) are components of stress vector, j=1,...,N, while q is the load perpendicular to the plane of the plate. The paper adopts a linear interpolation along the two adjacent layers so the number of nodes through the thickness n is for one higher than the number of layers N. For the j-th orthotropic layer, the connection of stresses and deformations are given with:

ìs x ü ïs ï ïï y ïï ís xy ý ïs ï ï xz ï ïîs yz ïþ

( j)

é Q11 Q12 ê êQ12 Q22 = êQ16 Q26 ê 0 ê 0 ê 0 0 ë

Q16 Q16

0 0

Q66 0

0 Q44

Q45

0 ù ú 0 ú 0 ú ú Q45 ú Q55 úû

( j)

ìex ü ïe ï ïï y ïï x íg xy ý ïg ï (5) ï xz ï ïîg yz ïþ

( j) where Qij - the plane stress-reduced stiffness-

es of the j-th orthotropic layer.

When the connections (5) are inserted in the formulas for the intersection forces (4) with respect of the assumed displacement field (1) and (2) as well as the known connections of deformations and displacements, we get the equations that define the dependence of the force and displacement. The method for determining the reduced stiffness of each layer and stiffness coefficient of layered palates that define the impact of one layer to another , and which are necessary for the calculation of the forces, are determined in the manner shown in the paper [03]. The paper argues that, for the adopted interpolation through the plate thickness, stiffness of layered plates depend on the thickness, the mechanical properties of layers and layers positioning relative to the middle plane of the plate. N zk +1

Aij = å

òQ

(k ) ij

(i, j = 1, 2, 6, 4, 5)

k =1 z j

N zk +1

D =å IJ ij

òQ

(k ) ij

y Iy J dz

(i, j = 1, 2, 6)

k =1 zk

N zk +1

D =å IJ ij

òQ

(k ) ij

y , Iz y , Jz dz

(i, j = 4, 5)

k =1 zk

N zk +1

BijJ = å

òQ

(k ) ij

y J dz

(i, j = 1, 2, 6)

k =1 zk

N zk +1

BijJ = å

òQ

(k ) ij

y , Jz dz

(6)

(i, j = 4, 5)

k =1 z k

104

Journal of Applied Engineering Science 14(2016)1, 359

Marina Rako!evi - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

ANALYTICAL SOLUTION

while satisfying boundary conditions are:

For simply supported layered plate dimensions with N layers which carry in directions of the x and y axis, material stiffness A16, A26, A45, BJ16, BJ26, BJ45, DIJ16, DIJ26 and DIJ45 are equal to zero, equations (6). The analytical solution to the problem is obtained on the basis of assumed change of componental displacements given in the form of double trigonometric series, [09]:

v = w = V J = N x = N xJ = 0

u = å X mn cos a x sin b y m,n ¥

v = å Ymn sin a x cos b y m, n ¥

w = å Wmn sin a x sin b y m,n

J U J = å Rmn cos a x sin b y m,n ¥

(7)

J V J = å S mn sin a x cos b y m, n

where: a =

mp np ,b = , J = 1,..., n a b ¥

{

x = 0, a ; J = 1, n

u = w = U = N y = N = 0 y = 0, b ; J = 1, n (8) J

J y

The load acting perpendicular to the plane of the plate is shown by trigonometric functions in the form of a double Furie series: ¥

q ( x, y ) = å Qmn sin a x sin b y

(9)

m, n

where Qmn coefficients that depend on the type of load. When the relations that represent the connection of forces and displacements are inserted into the equations (3) we get a system of equations for the observed problem. For each Furie s pair (m, n) is obtained a system of (3+2n) equations with the same number of unknown coefficients Xmn, Ymn, Zmn, Rjnm i Sjmn. When the obtained decisions are included in the relations (7), we get the values of unknown displacement. After determining function of overall displacements, the presumed number of trigonometric series members (m, n), the components of the deformation vector, and then the stress vector components for an arbitrary point of layered composite plates are being determined:

J =1

J J s x ( x, y, z ) = -å éëQ11 a ( X mn + å Rmn j J ( z )) +Q12 b (Ymn + å Smn j J ( z ))] sin a x sin b y} m,n ¥

{

J J j J ( z ) )] sin a x sin b y} (10) s y ( x, y, z ) = -å éëQ12 a ( X mn + å Rmn j J ( z )) + Q22 b (Ymn + å S mn m,n

J =1

m,n

J =1

J J s xy ( x, y, z ) = Q66 å {[ b ( X mn + å Rmn j J ( z )) + a (Ymn + å Smn j J ( z ) ) ] cos a x sin b y}

To determine interlayer stresses in the planes (x, z) and (y, z) is used approximate, semi-analythic, calculation process with the assumed parabolic distribution along each observed layer j [09]:

s xzj ( z ) = N1 ( z ) f1xj + N 2 ( z ) f 2 jx + N 3 ( z ) f3 xj s yzj ( z ) = N1 ( z ) f1 yj + N 2 ( z ) f 2 jy + N 3 ( z ) f 3 jy (11) where: z - coordinates of the local coordinate system the j-th layer of the plate,

f ixj , f iyj , i = 1, 2, 3 - unknown coefficients that rep-

resent shear stresses !xz and !yz at the ends and in the middle of the observed layer,N1(z), N2(z) and N3(z)- one-dimensional quadratic interpolation function. Journal of Applied Engineering Science 14(2016)1, 359

To determine the unknown coefficients f ix , fiy for each of the shear stresses is necessary to write 3N equations. These equations are determined from the following conditions: the shear stresses in the upper and lower fiber of the layer has a value of zero, stresses have the same value on connections of the layers, the condition of the average values of shear stress for each layer j is satisfied, and the values obtained from the constitutuve equation are met. PROGRAM STRUCTURE Schematic representation of ANSLACOP program algorithms based on mathematical model is shown in Figure 2. The program is made up of sub-programs with the following functions: 105

Marina Rako evi# - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

Data group 5: Angles of layers orientation; Data group 6: NFU, MFU - Number of elements of double series Data group 7: Intensity of load and load index; Data group 8: Coordinates of nodes through the thickness of the plate; Data group 9: Coordinates of the nodes in-

plane (x, y).

Figure 2: ANSLACOP program algorithm

INPUT - The sub-program INPUT is used for the downloading and preparing of the data necessary for the static analysis of layered composite simply supported plates. Input data are entered into the program over a previously formed INP. dat data file containing the following: Data group 1: Name of the problem Data group 2: The number of layers, the number of nodes through the thickness of the layered plate number of nodes in the plane (x, y) in which Data group 3: The width and length of the plate; Data group 4: Material characteristics of layers (Ei-elastic modules, Gij shear modules , ij Poisson s ratio); 106

VEK_Q The sub-program for each layer k downloads data relating to the material characteristics of layers Ei (i=1,2), Gij(i,j=1,2,3), ij(i=1,2), as well as the angles of the layers orientation. After that, for each layer k=1, N the calculation of values Q11, Q22, Q12, Q44, Q55, Q66 is performed as well as transformed material characteristics of layers ,[03]. H_LAYER - The sub-program downloads data from the input data file relating to the coordinates of nodes through the thickness of the plate and calculates the thicknesses of layers. Each layer may have different thickness. MAT_A - The sub-program downloads the results of the sub-program VEK_Q and H_LAYER and calculates the stiffnesses Aij from Eq.(6). MAT_B The sub-program downloads the results of the sub-program VEK_Q and H_LAYER and calculates the coefficients of stiffnesses BijJ from Eq. (6). MAT_D The sub-program downloads the results of the sub-program VEK_Q and H_LAYER and calculates the coefficients of stiffnesses DijIJ from Eq. (6). MAT_AA The sub-program downloads the results of previous sub-program and calculates the coefficients of the governing equations according to Eq. (3). LOAD The sub-program downloads the data on the load intensity and the index load (1 or 2) from the input data file and develops the load to a double trigonometric series Eq. (9). Load indexes are defined for uniformly and sinusoidal distributed transverse load. EQUAT The sub-program downloads the results of the previous sub-programs, solves the system (3+2n) and determines the unknown coefficients Xmn, Ymn, Wmn, Rmn and Smn for each pair (m,n) of the double trigonometric series. DISPL The sub-program calculates and sends in the output data file, OUT.dat, values of displacements according to the Eq. (1) and Eq. (7) at the points in the plane (x,y) and through the thickness of the plate. Journal of Applied Engineering Science 14(2016)1, 359

Marina Rako!evi - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

CONVERGENCE AND VERIFICATION OF RESULTS

STRESS1 The sub-program calculates stresses in the plane (x, y) according to relations Eq. (10) and sends the results of the calculation in the output data file OUT.dat MAT_AS, FREE_AS1,EQUAT, FREE_AS2, EQUAT and STRESS2 - The sub-programs calculate the shear stresses !xz and !yz by applying approximate methods shown in this paper, relations Eqs. (11), with the fulfillment of conditions specified in the shown procedure. After the calculation, the values of these stresses are sent in the output data file OUT.dat. The execution of the program formes the output file OUT.dat with the values of the displacement and the stress at predetermined points simply supported rectangular layered composite plate that are defined in the input file INP.dat.

in the middle of the three-layer square plate 0o/90o/0o for side-to-thickness ratio a/h=4 and a/h=10 and with material properties of a ply E1/ E2=25, G12=G13=0.5E2, G23=0.2E2, 12= 13=0.25, under uniformly distributed load. It is concluded that the analytical solution rapidly converges to the exact solution, Figures 3-4.

Figure 3: The dimensionless maximum deflection ( w) versus number of elements of double series (m,n) for side-to-thickness ratio a/h=4 and cross-ply 0º/90º/0º laminate

Figure 4: The dimensionless maximum deflection versus number of elements of double series (m,n) for side-to-thickness ratio a/h=10 and cross-ply 0º/90º/0º laminate

The convergence of analytical solutions depending on the number of elements of double series is shown in the example of changes of dimensionless deflection:

100 E2 w q0 hs 4

Table 1: The dimensionless maximum deflection in simpy supported square laminates 0º/90º/0º under sinusoidally distributed transverse load a/h

CLPT

0.4313

FSDT

1.9122

0.6949

TSDT

1.9218

0.7125

ANSLACOP

1.9670

0.7402

Table 1 contain value of the dimensionless maximum deflection for simpy supported square laminates 0º/90º/0º obtained with clasical laminate plate theory (CLPT) , first-order shear deformation theory (FSDT), third-order shear deformation plate theory (TSDT) (Reddy [1], page 612, table 11.4-1), and presented program ANSLACOP under sinusoidally distributed transverse load versus side-to-thickness ratio a/h.

Journal of Applied Engineering Science 14(2016)1, 359

CONCLUSION Analytical solution based on a mathematical model of Partial Layerwise Theory obtained by applying the program ANSLACOP converges very fast depending on the adopted number of items in the double trigonometric series and is numerically stable. The special significance of the presented analytical solution to the problems of bending of anisotropic laminated plates reflects in its use as 107

Marina Rako!evi - Analytical solution for simply supported laminated composite plates based on partial layerwise theory

a test solution for the solutions obtained by using numerical methods. Bearing in mind that in the stress-deformation analysis are mainly used software packages (ANSYS, ABAQUS, etc.) based on the finite element method this program can be used as a test solution for the solutions obtained by using these programs for thick and moderately thick simply supported layered composite plates loaded to bending. REFERENCES 1) J.N. Reddy, Theory and analysis of laminated composite plates , Mechanics of Composite Materials and Structures, 1999, 1-79 2) J.N. Reddy: Mechanics of Laminated Composite Plates - Theory and Analysis , Department of Mechanical Engineering, Texas A&M University ,1997 3) M. Rako!evi", #. Vuksanovi": Analitical solution of laminated rectangular composite plates , Monograph Researches , Editor A.Vujovi", Faculty of Civil Engineering, Podgorica, 2002, 253-266

4) M. Rako!evi", N.Vatin: Bending of laminated composite plates , Applied Mechanics and Materials, Vols. 725-726,2015, 667-673 5) M. Rako!evi": Prora!un krutosti slojevitih kompozitnih plo!a , Internacionalni nau!no stru!ni skup GNP, Zbornik radova-knjiga 1,2006,20-24 6) M. Rako!evi": Savijanje debelih i umjereno debelih slojevitih kompozitnih plo!a , Me$unarodna konferencija savremena dostignu"a u gra$evinarstvu, Gra$evinski fakultet Subotica, Zbornik radova, 2014, 24-25 7) M. Rako!evi": Teorijski modeli slojevitih kompozitnih plo!a , Tre"i internacionalno nau!no-stru!ni skup GNP, Zbornik radova, 2010, 141-146 8) M. Rako!evi": Approximate procedure for calculation of shear stresses %xz and %yz , Journal of Applied Engineering Science, 10 (1), 2012, 37-42 9) M.Rako!evi": Prora!un sastavljenih slojevitih plo!a , Gra$evinar, 63, 2011, pp. 819-825 Paper sent to revision: 10.02.2016. Paper ready for publication: 15.03.2016.

108

Journal of Applied Engineering Science 14(2016)1, 359

Original Scientific Paper

doi:10.5937/jaes14-10471

Paper number: 14(2016)1, 360, 109 - 114

SHEAR RESISTANCE OF LONGITUDINAL SHEAR CONNECTION WITH GROUPS OF HEADED STUDS Milan Spremi! University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Zlatko Markovi! University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Jelena Dobri! University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Dragan Bu"evac University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia The frequently applied solution for shear connection in steel and concrete precast composite structures is the discontinuous shear connection with a headed stud in group arrangement. Application of shear connection with headed studs in group arrangement and calculation of shear resistance for studs group in typical precast composite floor beam is presented. The possibility and feasibility of shear connection construction with headed studs in group arrangement was considered. It is shown that the shear connection in precast composite floor beams can be constructed with a group of four headed studs. Key words: Prefabricated composite beams, Shear connection, Group of headed studs INTRODUCTION In designing and constructing prefabricated composite structures, the most common realization of longitudinal shear connection between steel and concrete is implementation of headed studs in a group arrangement. Groups of headed studs can be used for subsequently executed shear con-

nection. Headed studs in group arrangement can be successfully applied for the reinforcement and renovation of the existing longitudinal shear connection between structural steel and concrete slab. Figure 1 presents the solution for subsequently executed shear connection with group of headed studs placed in hole in concrete made by drilling.

Figure 1: Subsequently executed shear connection, geometry of studs group , 359 * University of Belgrade, Faculty of Civil Engineering, Bulevar kralja Aleksandra 73, Belgrade, Serbia spremic@grf.rs

109

Milan Spremi - Shear resistance of longitudinal shear connection with groups of headed studs

In an opening with 120-150 mm in diameter four headed studs in a group can be made, with reduced values of longitudinal direction according to the minimum prescribed in actual codes. The reduction of the spacing between the adjacent headed studs is aimed to form a group of smaller dimensions, which eventually results in small dimensions of a hole in the RC slab, and a smaller discontinuity of an RC slab. The paper has shown that with a group of four headed studs having diameter of 16 or 19 mm a full longitudinal shear connection can be realized for a standard composite beam of a span up to 12,0 m. When the longitudinal shear connection is constructed with the headed studs in a group, the shear connection can be characterized as discontinuous. The groups of headed studs are constructed in discreet locations on the beam at the openings in prefabricated RC slab. It is two possibilities for the arrangement of the headed studs in the group: - With minimum prescribed distances between the headed studs or - With the smaller distances between the headed studs than the prescribed minimum. This paper presents the calculation of longitudinal shear connection, with studs in group arrangement. The studs group with smaller distances between the studs in shear force direction, than the prescribed minimal distances in Eurocode 4, was considered in typical composite floor beam. SHEAR RESISTANCE OF HEADED STUDS GROUP Among all the standing regulations, groups of headed studs are mentioned as a structural solution of the shear connection in EN 1994-2 [07] and Standard Specifications for Steel and Composite Structures published by JSCI [04]. According to EN 1994-2 headed studs may be placed in groups. In this case consideration of: non-uniform flow of longitudinal shear, the greater possibility of slip and the local resistance of the concrete slab, must be provided. For design and calculation of longitudinal shear connection with headed studs in group arrangement JSCI [04] refer to research realized and published by Okada et al. [01]. Design shear resistance for a group of headed studs could be determined as sum of single headed studs shear resistances:

PRd,G = å PRd 110

(1)

The previous expression can be used when headed studs are constructed at the distances prescribed by the technical regulation. If the minimum prescribed distances between the headed studs according to EN1994-1-1 [03] or ASCE, 5d and 6d respectively are used, the dimensions of the group are up to two times bigger than the dimensions of the group constructed with the reduced distances between the headed studs. In order to reduce the dimensions of the group, it is necessary to reduce the distance between the headed studs el in the direction of the shear force. The prescribed minimum distances perpendicular to the direction of the shear force et are negligibly bigger than the technologically minimal required distance which is around 2d. When the groups of headed studs are constructed with the distances between the headed studs being el<5d it is necessary to reduce the shear resistance in some cases. The shear resistance of a group with the reduced distance between the studs is equal:

PRd,G = a G × å PRd

(2)

The value !G in the previous equation presents the reduction factor for shear resistance (!G"1). All existing recommendations for calculation of shear resistance, for headed studs in group arrangement, are based on the reduction factor. Many authors have researched in the recent years the shear resistance and behavior of a group of headed studs in longitudinal shear connections. Experimental research of group shear resistance with reduced distance between the studs in the shear force direction were realized only by Spremic [06] and Shim C.S. [05]. In three studies, the authors proposed and provided recommendations for the calculation of shear resistance of a headed studs in group arrangement: - Okada et al. [01] analyzed the shear resistance of a group of nine studs in the 3x3 arrangement. In the framework of the experimental tests, they did not test the shear resistance of the group with reduced values of distances between the headed studs. As the result of the research, they proposed the calculation procedure of the reduction coefficient which is the function of the distance between the headed studs and compressive strength of concrete:

PRd,G = f (el , f ck ) × å PRd

(3)

Journal of Applied Engineering Science 14(2016)1, 360

Milan Spremi! - Shear resistance of longitudinal shear connection with groups of headed studs

- Shim C.S. et al. [05] in their research has experimentally tested groups of nine headed studs in 3x3 arrangement. The research included also the headed studs group with reduced distances between the studs, 3d and 4d, in the shear force direction. The value of the proposed reduction coefficient in research [6] is a linear function of distance between adjacent headed studs:

PRd,G = f (el ) × å PRd

(4)

- Spremic [06] within his research, experimentally analyzed shear resistance and behavior of 4 headed studs in 2x2 arrangement. The dimensions of the group are adapted to the typical composite floor beams in buildings. The result of the research is a proposed procedure, for calculation of shear resistance of a group of headed studs which is the function of the group geometry and not only of the distance between the headed studs. The value of the reduction factor is in relation with: diameter of single studs in a group d, headed stud height hsc, number of studs in a group in direction of shear force - nr, number of studs in a group perpendicular to the direction of shear force -nc and the distance between the studs in direction of shear force el (3d<el<5d).

PRd,G = f (d , hsc , nc , nr , el ) × å PRd

(5)

The value of the reduction factor according to the solution proposed by Okada et al. [01] is less than 1, even in the cases when the distances between the headed studs are higher than 5d. This is not in agreement with the presented results of experimental researches. The value of reduc-

tion factor according to Shim C.S. [05] provides good results only in case of the group of headed studs which is, in terms of the group dimensions and dimension of individual stud, similar to experimentally tested specimens in [05]. In other cases, the proposed solutions from [06] is prominently conservative. The table 1 shows the reduction factor values for the group of four headed studs having diameters 12, 16 and 19 mm in 2x2 arrangement. The reduction factor according to the proposal from [03] and [06] have the same values for all three analyzed groups which is in opposite to the available experimental results. The detailed comparative analysis of the reduction factor values which were proposed in the mentioned researches are presented in [06]. SHEAR CONNECTION WITH STUDS GROUP On the examples illustrating typical composite beams in the building structures, the potential for implementation was analyzed and justification for application of the group of headed studs for construction of a longitudinal shear connection. The prefabricated floor structure, with the composite beams having spans 8, 10 and 12 m, was analyzed, see table 2. The adopted spacing of floor beams was 4.0 m. Dimensions of the prefabricated RC beams were adopted in accordance with the span of the floor structure. The RC slab width 1000-1400 mm is assumed. The width of the slabs must be adapted to distance between the groups, with the one group placed in the hole at the middle of precast concrete slab and the next group is placed between the concrete slabs, see Figure 2.

Table 1: Reduction factor value

Group Layout

d [mm]

hsc [mm]

2x2 2x2 2x2

12 16 19

100 100 100

3d 3d 3d

Spremic [6] 1.00 0.95 0.86

!G Okada [5] 0.82 0.82 0.82

Shim C.S. [4] 0.67 0.67 0.67

Table 2: Analyzed typical composite floor beams

Beam span L1[m] Beam distance " [m] Depth of concrete slab hc [m] Journal of Applied Engineering Science 14(2016)1, 360

PN1 8 4 16

PN2 10 4 16

PN3 12 4 16 111

Milan Spremi! - Shear resistance of longitudinal shear connection with groups of headed studs

Figure 2: Composite beam with precast RC slab Table 3: Steel cross section, capacity check in construction stage

Beam PN1 PN2 PN3

Ma,Ed [kNm] 172.8 236.3 388.0

Structural steel cross section IPE 330 IPE 400 IPE 500

Mpl,a,Rd [kNm] 221.2 359.4 603.4

Ma,Ed/Mpl,a,Rd

Va,Ed/Va,Rd

0.781 0.657 0.644

0.180 0.140 0.140

Table 4: Capacity check for composite cross section

Beam PN1 PN2 PN3

MEd [kNm] 424.8 630.0 955.8

MRd [kNm] 522.1 735.6 1223

MEd/MRd 0.814 0.856 0.782

The characteristic value of load is in all according to EN1991-1-1. Additional dead loads from cladding, walls and installation were adopted as value of 2.5 kN/m2 in total. The live load has the intensity of 3.0 kN/m2, which corresponds to the categories of loaded surfaces A to C2 according to EN19911-1. Steel grade for structural steel is S275. The characteristic value of the compressive strength fck according to EN 1992 for concrete C35/45 was adopted. All the adopted cross sections are class 1. The adopted dimensions of structural steel cross section and bearing capacity check in the construction stage are presented in Table 3. In construction stage the lateral-torsional buckling for structural steel part of cross section was not analyzed. It is possible to laterally stabilize the beam using the structural measures. According to Hicks and Lawson recommendations [08], direction for assembly of the precast RC slab from the supports towards the middle of the span, lateral torsional buckling can be prevented. The value of the plastic resistance moment of composite cross sections of the as well as the proof of bearing capacity were presented in the 112

VEd [kN] 212.4 252.0 318.6

VRd [kN] 489.2 677.0 950.6

Va,Ed/Va,Rd 0.434 0.372 0.335

table 4. For the adopted spacing of floor beams of 4.0 m the slab thickness of 16.0 cm was adopted. Starting from the shear resistance of the single headed stud PRd, the required number of headed studs for the full shear connection between the structural steel and concrete slab was calculated. Arrangement and distance at which the headed studs can be located in the longitudinal shear connection depends on the deformation characteristics of the connector. Regarding the behavior, it is habitual in literature to divide the connectors into rigid and elastic Â&#x2013; ductile connectors. The elastic-ductile connector, like headed studs, are characterized primarily by high deformability and ability to achieve prominent plastic deformations before the shear failure. The rigid Â&#x2013; block connectors receive the shear forces exclusively by shearing, and at ultimate strength they exhibit negligible plastic deformations. Deformability of the connectors, provides redistribution of the total shear force onto a large number of connector which must transfer the force between the steel section and the concrete slab. Headed Journal of Applied Engineering Science 14(2016)1, 360

Milan Spremi! - Shear resistance of longitudinal shear connection with groups of headed studs

studs having sufficient deformation capacity to allow ideal plastic behavior of the longitudinal shear connection can be considered elastic or ductile. Eurocode 4 provides a condition for the experimental proof of headed studs ductility. According to Eurocode 4 the headed stud is elastic- ductile, if the characteristic slip at the ultimate shear load of headed studs is !uk>6 mm. According to experimental results presented by Spremic et al. [09], a group of four headed studs 16 mm in diameter, 2x2 arrangement can be considered as ductile, see Figure 3. Ductility of the longitudinal shear connection realized using groups of headed studs allows implementation of partial shear connection for design and calculation of shear connection between the structural steel and concrete slab. This fact allows adopting even higher values of distance between the groups, if required by the structural design. According to results from [9], for small reductions of the number of connectors, there is no significant reduction of cross section bearing capacity . By construction of shear connection with ductile headed studs, the required number of headed

Figure 3: Load Â&#x2013; Slip diagram for group of four headed studs d=16mm h=100 mm

studs for the transfer of longitudinal shear force can be distributed in the part of the beam between the support point and the cross section withstanding the maximum value of bending moment. The Table 5 presents the results of the longitudinal shear connection calculation of the analyzed composite floor beams. The structural design of the longitudinal shear connector with groups of headed studs means grouping of the individual headed studs. The adopted group for design of the shear connection is the group of four headed studs in 2x2 arrangement. The larger groups of headed studs are not suitable for floor beams in buildings because of the limited width of the upper flange of the beam which is used for placing of the headed studs. The results of the calculation according to Spremic [05] with required number of studs groups and adopting distance between the groups which are required for the full shear connections in case of the analyzed floor beams are presented in table 6. In the case of plastic redistribution of longitudinal shear force along the steel beam, which is applicable in case of ductile connectors, an equal value of distance between the groups of headed studs along the beam can be adopted. This assumption is in agreement with the results of experimental results presented in the Figure 3. As presented in the previous table, the values of distances of the groups of headed studs in the direction of shear force ranges between 480 mm and 540 mm. These distances are in agreement with the structural design of reinforced concrete slab, which is produced in the widths of 1000 mm or 1200 mm by most of the manufacturers of prefabricated concrete elements. When the beam span is larger than 12.0 m, the serviceability limit state, deflections and vibration become the criteria which are relevant for design of floor beams.

Table 5: Longitudinal shear connection Â&#x2013; Results

Beam PN1 PN2 PN3 PRd Vl,Ed n

PRd d hsc [kN] [mm] [mm] 16 100 63.1 16 100 63.1 19 100 88.9 design shear resistance of single headed studs design value of shear force number of headed studs for full shear connection

Journal of Applied Engineering Science 14(2016)1, 360

Vl,Ed [kN] 1721.5 2323.8 3190.0

n [kom] 27.3 36.8 35.9

113

Milan Spremi! - Shear resistance of longitudinal shear connection with groups of headed studs

Table 6: Longitudinal shear connection with groups of headed studs

Group layout d x hsc !G [mm] [nl × nt] PN1 16x100 2x2 0.95 PN2 16x100 2x2 0.95 PN3 19x100 2x2 0.86 !G reduction factor for shear resistance PRd,G design shear resistance of headed studs group ng number of studs group, eg distance between studs group Beam

CONCLUSION Based on these presented results it is concluded that the headed studs in grouped arrangement can be successfully used as the design and construction solution of the longitudinal shear connection for the prefabricated composite beams in typical floor structures. The following can also be concluded: - In design of the shear connection with groups of headed studs, ductility of a group of headed studs must be proven in order to adopt equal distances between the groups of headed studs on a structural steel. - A group of four headed studs having diameter 16 mm and 100 mm of height behaves ductile even in case when the distance between the headed studs is smaller than the prescribed 5d. A partial shear connection can be constructed in the cases when the distance between the groups is larger than the distances provided by the calculation. - A group of four headed studs having diameter 16 mm or 19 mm can be used for construction of a full shear connection for the standardized floor beams having span of up to 12.0 m. The required distance between the groups is within 450-600 mm limits. - For a group of four headed studs with d=16 mm and hsc"100 mm shear resistance reduction is not required, as well as in the cases when the distance between the headed studs is less than 5d but more than 3d. REFERENCES 1) Hicks S.J., Lawson R.M., Design of Composite Beams Using Precast Concrete Slabs, SCI PUBLICATION P287, The Steel Construction Institute, 2003 114

PRd,G [kN] 224.6 224.6 283.6

ng [kom] 7.66 10.3 11.3

eg [cm] 52.2 48.5 53.6

2) EN1994-1-1, Eurocode 4, Design of Composite Steel and Concrete Structures. General Rules and Rules for Buildings , CEN (European Committee for Standardization), December 2004. 3) EN1994-2, Eurocode 4, Design of Composite Steel and Concrete Structures. General Rules and Rules for Bridges , CEN (European Committee for Standardization), 2005. 4) Okada J, Yoda T, and Lebet J.P, The Study of the Grouped Arrangements of Stud Connectors on Shear Strength Behavior , Structural Eng./Earthquake Eng. JSCE, Vol. 23, No. 1, pp. 75-89. 5) Shim C.S, Lee P.G, Kim D.W. and Chung C.H, Effects of Group Arrangement on the Ultimate Strength of Stud Shear Connection , Proceedings of the 2008 Composite Construction in Steel and Concrete Conference VI, ASCE Conf. Proc. doi:10.1061/41142(396)8. 6) Spremic M, The analysis of headed studs group behavior in composite steel-concrete beam , PhD thesis, University of Belgrade, Faculty of Civil Engineering, October 2013 7) Spremic M, Markovic Z, Veljkovic M, Budjevac D, Push out experiments of headed shear studs in group arrangements, Advanced Steel Construction; Vol. 9, No. 2, pp. 170 191, 2013. 8) Spremi# M., Budjevac D., Markovi# Z., Dobri# J., The comparative analysis of the full and partial shear connection of composite beams , International conference GNP 2008, abljak, Podgorica 2008. 9) Standard Specifications for Steel and Composite Structures, Japan Society of Civil Engineers, December, 2009. Paper sent to revision: 03.02.2016. Paper ready for publication: 15.03.2016. Journal of Applied Engineering Science 14(2016)1, 360

Original Scientific Paper

Paper number: 14(2016)1, 361, 115 - 120

doi:10.5937/jaes14-10473

FREE VIBRATION ANALYSIS OF SPATIAL FRAMES WITH VARIOUS BOUNDARY CONDITIONS Ljiljana ugi! University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro Stanko Br"i# University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro piro Gop"evi# University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro Free vibration analysis of the spatial frames consisting of 3D beam elements is presented in the paper, using the consistent mass matrix, as implemented in the code ALIN, which is written in C++. The values of circular frequencies for the spatial simply supported and clamped-clamped beam, obtained by using ALIN, are compared with the exact solutions and the solutions obtained by using the code TOWER. In order to obtain better, more exact, results, it is necessary to discretize the frame into more finite elements. As opposed to TOWER, which is using the lumped mass matrix, the code ALIN is using the consistent mass matrix, thus allowing wider discretization, into smaller number of finite elements, then in the case of TOWER. Key words: Prefabricated composite beams, Shear connection, Group of headed studs INTRODUCTION

qT = [ ui vi wi !xi !yi !zi uj vj wj !xj !yj !zj ]

Spatial frames in reality are systems with continuously distributed mass, i.e. systems with infinite number of degrees of freedom. In order to simplify calculation of such systems, continuous mass is substituted by consistent or concentrated mass. Formulation of the consistent mass matrix, applied in this paper and implemented in the originally developed code ALIN, is using the same interpolation functions used in the formulation of the stiffness matrix. Consequently, the consistent mass matrix of beam elements is of the same structure as the stiffness matrix. The concentrated mass matrix of elements has a diagonal structure, which is exacty the reason of its frequent implementation in the commercial computer codes, such as TOWER.

RT = [Ni Tyi Tzi Mxi Myi Mzi Nj Tyj Tzj Mxj Myj Mzj ] (2)

ANALYSIS OF BEAM ELEMENT IN SPACE The spatial frames in this paper are represented by 3D beam finite elements with two nodal points and with six dofs at each node. Generalized displacements and the corresponding generalized forces in nodes i and j are the components of the vector of generalized displacements q and the vector of generalized forces R

(1)

The stiffness matrix of the 3D beam element k (3) may be obtained by the principle of superposition, i.e. by separation of the spatial state of stress of the element into: axial state, bending in the plane xy, bending in the plane xz and the torsion, [03]: é EA ê L ê ê 0 ê ê ê 0 ê ê ê 0 ê ê ê 0 ê ê ê 0 k =ê ê EA ê- L ê ê 0 ê ê ê 0 ê ê ê 0 ê ê ê 0 ê ê ê 0 ë

12EI z L3

6EI z L2

12EI y L3

0 0

0 -

6EI y L2

0 GI x L 0

0 6EIz L2

6EI y L2 0

L3 0 6EI y

0 GI - x L

L2 0

2EI y

EA L

6EI z L2

12EIz L3

0 GI - x L 0 0

6EI y L2 0 2EI y L 0

0 0 0 2EI z L

* Faculty of Civil Engineering, University of Montenegro, Cetinjski put bb, 81000 Podgorica, Montenegro ljiljaz@ac.me

0 0

6EI - 2z L

12EI y L3 0 6EI y L2 0

0 6EI y

12EIz L3

0 12EI y

12EI z L3

6EI - 2z L

0 4EI y

EA L

4EI z L

6EIz L2

12EI y

6EI y

0 GIx L 0 0

0 6EI y L2 0 4EI y L 0

ù 0 ú ú 6EIz ú L2 ú ú 0 ú ú ú 0 ú ú ú 0 ú ú 2EI z ú ú L ú ú 0 ú ú 6EI z ú - 2 L ú ú 0 ú ú ú 0 ú ú ú 0 ú ú 4EI z ú ú L û

(3)

115

Ljiljana ugi! - Free vibration analysis of spatial frames with various boundary conditions

Mass matrix of the beam element

the consistent mass matrices are:

As it is well known, connection between the vector of the generalized inertial forces Fin and the && is estabvector of generalized accelerations q lished by the mass matrix m of the element:

é ê ÁAL ê msz = 420 ê ê ë

&& Fin = - mq

(4)

Mass matrix m is determined by the expression:

m = ò N ÁNdV T

(5)

where ! is the mass density of the material, and N is the matrix of interpolation functions. Mass matrix defined by (5) is called the consistent mass matrix if the same interpolation functions are used as for the displacement field within the element. This mass matrix may be obtained in the same way as the stiffness matrix (3), using the principle of superosition, i.e. by separation of the spatial state of stress into axial state, bending in the plane xy (about z axis), bending in the xz plane (about axis y) and the torsion. Consequently, expression (4) may be presented as:

é Fa ù ém a êF ú ê ê sz ú =- ê ê Fsy ú ê ê ú ê ë Ft û ë

m sz msy

&&a ù ù éq ú êq && ú ú ê sz ú &&sy ú ú êq úê ú && t û mt û ë q

(6)

where ma is the mass matrix of axial vibrations, msz and msy are mass matrices of transverse vibrations in planes xy and xz, and mt is the mass matrix of torsional vibrations of the element. If for the beam element under axial loading one assumes the interpolation functions as follows:

N = [1- x x] , x =

x L

(7)

the consistent mass matrix is obtained as:

ma =

ÁAL é 2 1 ù 6 êë 1 2 úû

(8)

If the beam element is exposed to bending in the plane xy, i.e. xz and if the corresponding interpolation functions are L Hermite s polynomials of the first kind: N = [ 1 - 3x 2 + 2x 3 L(x - 2x 2 + x 3 ) 3x 2 - 2x 3 L(-x 2 + x 3 ) ], x =

x L

(9) N = [ 1 - 3x 2 + 2x 3 L(-x + 2x 2 - x 3 ) 3x 2 - 2x 3 L(x 2 - x 3 ) ], x =

x L

(10) 116

156

22L

22L 54

4L 13L

13L 156

-13L

-3L2

-22L

é 156 ê ÁAL ê -22L msy = 420 ê 54 ê ë 13L

-22L

-13L ù -3L2 úú -22L ú ú 4L2 û

-13L

156

-3L

22L

(11)

13L ù -3L2 ú ú 22L ú ú 4L2 û

(12)

If one assumes linear distribution of the angle of twist of the beam element exposed to Saint Venant s free torsion, i.e. if linear interpolation functions are assumed:

N = [1- x x] , x =

x L

(13)

the consistent mass matrix is obtained as:

mt =

ÁI0 L é 2 1 ù 6 êë 1 2 úû

(14)

where I0 is the polar moment of inertia of the cross section of the beam element. The consistent mass matrix of 3D beam element (15) is obtained from mass matrices ma, msz, msy and mt, which are given by expressions (8), (11), (12) and (14). Its elements are positioned at the corresponding locations according to the order of generalized accelerations and generalized inertial forces, corresponding to the order of the generalized displacements and forces (first for the node i and then node j), as given by expressions (1) and (2). 0 0 0 é140 ê 0 0 0 156 ê ê 0 0 0 156 ê 140I0 ê 0 0 0 ê A ê 0 0 0 -22L ê 0 0 22L ÁAL ê 0 m= ê 0 0 0 420 ê 70 ê 0 54 0 0 ê 0 54 0 ê 0 ê 70I0 0 0 ê 0 A ê ê 0 0 0 13L ê 0 0 ë 0 -13L

0 0 0 22L 0 -22L

0 0 0 70I 0 0 0 0 0 0 A 0 0 0 0 4L2 -13L 2 0 13L 0 0 0 4L 0 0 140 0 0 0 0 13L 0 156 0 0 0 0 0 0 156 -13L 140I 0 0 0 0 0 0 A 0 0 0 0 -3L2 22L 0 -3L2 0 -22L 0 0 70 0 0

0 54 0

0 0 54

0 0 13L

0 ù -13L úú 0 ú ú 0 0 ú ú 0 ú -3L2 ú 0 -3L2 ú ú 0 0 ú 0 -22L ú ú 0 ú 22L ú 0 0 ú ú 0 ú 4L2 2 ú 0 4L û

(15) In order to simplify analysis and calculation, the total inertial force of the finite element is uniformly distributed as concentrated forces at nodes, Journal of Applied Engineering Science 14(2016)1, 361

Ljiljana ugi! - Free vibration analysis of spatial frames with various boundary conditions

by using the concentrated mass matrix. It has a diagonal structure due to assumption that accelerations of the element in direction of some generalized displacement are generating inertial forces only in that direction. In this case, for the 3D beam element, the concentrated mass matrix is given as:

ÁAL I 2

(16)

where I is the unit matrix of the twelfth order. In order to further simplify, one may assume that certain diagonal elements of the concentrated mass matrix (16) are equal to zero, i.e. one may assume that not all degrees of freedom are of the same importance in dynamic analysis (e.g. by neglecting the influence of the so-called rotational inertia terms). ANALYSIS OF FREE VIBRATIONS OF THE SYSTEM Differential equations of motion of the free undamped vibrations of the system, in the matrix form, are given as:

&& + Kq = 0 Mq

(17)

where M and K are mass and stiffness matrices, while q and are the vectors of the generalized displacements and accelerations of the nodes of the system. In solution of Eqs. (17) one assumes that all generalized displacements of nodes qi(t) (i=1,2,...,n) are changing synchronously and synphasely. Therefore, the solution of Eqs. (17) is assumed as:

q(t) = q cos(Ét - f )

(18)

where q - constant vector of order n, ! - circular frequency of free vibrations and " - phase angle of free vibrations. If assumed solution (18) is inserted into Eqs. (17), one obtains: (19) (K - É 2 M ) q = 0 Relation (19) represents, in the mathematical sense, the eigenvalue problem of the pair of matrices K and M. It is necessary to determine the values ! 2 for which there is a non-trivial solution for constants q . The system of homogeneous algebraic equations (19) has a non-trivial solution if the determinant of the system is equal to zero, i.e.: ù é (20) det K - É 2 M = 0

êë

úû

Journal of Applied Engineering Science 14(2016)1, 361

If expression (20) is developed, it represents the characteristic polynomial equation of order n in !2. Since matrices K and M are symmetric and positive definite, all roots of the characteristic polynomial equation are real, positive ane mutually different: !12, !22,..., !n2. They represent the eigenvalues of the system, while the square roots of these values: !1, !2,...,!n are the natural circular frequencies of the system, where:

(K - É 2r M ) q r = 0

( r = 1, 2,..., n )

(21)

Since equations (21) are homogeneous, elements of the eigenvector q r are determined up to the constant factor. The eigenvalue problem of the pair of matrices K and M (19), represents the generalized eigenvalue problem, which, by the corresponding transformations [02], may be reduced to the standard eigenvalue problem: (22) Ax = » x Advantages of transformation of the generalized eigenvalue problem into the standard problem is in the fact that there are more very efficient algorithms for the solution of the standard eigenvalue problem (e.g. Jacobi and Lanczos algorithm). NUMERICAL EXAMPLE Incorporating previously discussed solutions, the computer code ALIN was developed [05], using programming language C++. The code is oriented to dynamic analysis of spatial frames, in this case to free vibration analysis of spatial frames. Using the code ALIN, this paper is presenting the free undamped vibration analysis of two spatial girders (Figures 1-2), which are different only in boundary conditions: one is the spatial simply supported beam, and the other is a clampedclamped beam. Obtained values of circular frequencies are compared with results obtained using the code TOWER and also with exact solutions obtained for the continuous systems with infinite number of dofs, given in literature [02]. Tabeles 1-4 are presening the values of circular frequenciies of free undamped vibrations for the first three modes in plane xy, i.e. xz, of considered beams, obtained by ALIN and TOWER, using different discretizations into finite elements. The cases when beams are treated as a single finite element and then discretizad into 2, 3, 4 and 5 finite elements are considered. Obrained values of circular frequencies are compared with exact values obtained from [02]. 117

Ljiljana Â&#x17D;ugi! - Free vibration analysis of spatial frames with various boundary conditions

Figure 1: Spatial simply supported beam

Figure 2: Spatial clamped-clamped beam Tabeles 1-4 are presening the values of circular frequenciies of free undamped vibrations for the first three modes in plane xy, i.e. xz, of considered beams, obtained by ALIN and TOWER, using different discretizations into finite elements. The cases when beams are treated as a single

finite element and then discretizad into 2, 3, 4 and 5 finite elements are considered. Obrained values of circular frequencies are compared with exact values obtained from [02].

Table 1: Circular frequencies of free vibrations in xy plane of a spatial simply supported beam Circular frequencies [rad/s]

Mode

Exact

ALIN

TOWER

Difference [%]

sol. [4]

1f.e

2f.e

3f.e

4f.e

5f.e

2f.e

3f.e

4f.e

5f.e

/1/

/2/

/3/

/4/

/5/

/6/

/7/

/8/

/9/

/10/

61.10

67.81

61.34

61.15

61.11

61.10

60.43

60.82

60.88

60.89

/2/-/1/

10.99

244.39

310.75

271.25

245.35

245.33

244.79

232.59

239.15

240.52

27.16

549.87

681.80

610.31

55.91

554.23

496.50

521.69

118

/3/-/1/

/4/-/1/

/5/-/1/

/6/-/1/

/7/-/1/

/8/-/1/

/9/-/1/

/10/-/1/

0.39

0.08

0.03

0.01

-1.10

-0.45

-0.36

-0.33

10.99

1.18

0.39

0.17

-4.83

-2.14

-1.58

23.99

10.99

1.83

0.79

-9.71

-5.12

Journal of Applied Engineering Science 14(2016)1, 361

Ljiljana Â&#x17D;ugi! - Free vibration analysis of spatial frames with various boundary conditions

Table 2: Circular frequencies of free vibrations in xz plane of a spatial simply supported beam Circular frequencies [rad/s]

Mode

Exact

ALIN

TOWER

Difference [%]

sol. [4]

1f.e

2f.e

3f.e

4f.e

5f.e

2f.e

3f.e

4f.e

5f.e

/1/

/2/

/3/

/4/

/5/

/6/

/7/

/8/

/9/

/10/

45.82

50.86

46.00

45.86

45.83

45.39

45.68

45.72

45.73

183.29

412.40

233.06

203.44

511.35

185.45

457.73

184.01

415.68

183.59

415.68

175.66

180.47

378.25

181.43

/2/-/1/

/3/-/1/

/4/-/1/

/5/-/1/

/6/-/1/

/7/-/1/

/8/-/1/

/9/-/1/

/10/-/1/

10.99

0.39

0.08

0.03

0.01

-0.94

-0.31

-0.22

-0.20

27.16

10.99

1.18

0.39

0.17

-4.17

-1.54

-1.01

23.99

10.99

1.83

0.79

-8.28

-3.74

396.97

Table 3: Circular frequencies of free vibrations in xy plane of a spatial clamped-clamped beam Circular frequencies [rad/s]

Mode

Exact

ALIN

TOWER

Difference [%]

sol. [4]

1f.e

2f.e

3f.e

4f.e

5f.e

2f.e

3f.e

4f.e

5f.e

/1/

/2/

/3/

/4/

/5/

/6/

/7/

/8/

/9/

/10/

/2/-/1/

138.50

140.74

139.07

138.68

138.57

119.58

134.29

135.92

136.25

381.78

398.40

385.31

383.30

307.38

353.70

364.14

748.43

764.42

758.79

571.56

657.93

/3/-/1/

/4/-/1/

/5/-/1/

/6/-/1/

/7/-/1/

/8/-/1/

/9/-/1/

/10/-/1/

1.62

0.41

0.13

0.05

-13.66

-3.04

-1.86

-1.62

2.00

0.92

0.40

-7.35

-4.62

2.14

1.38

-23.63

-12.09

Table 4: Circular frequencies of free vibrations in xz plane of a spatial clamped-clamped beam Circular frequencies [rad/s]

Mode

Exact

ALIN

TOWER

Difference [%]

sol. [4]

1f.e

2f.e

3f.e

4f.e

5f.e

2f.e

3f.e

4f.e

5f.e

/1/

/2/

/3/

/4/

/5/

/6/

/7/

/8/

/9/

/10/

/2/-/1/

103.87

105.56

104.30

104.01

103.93

90.24

101.41

102.62

102.86

286.33

292.05

288.98

287.48

233.63

269.63

277.27

561.33

573.31

569.09

When using ALIN, if the beam is not divided into smaller segments, i.e. if the beam is a single finite element, the first and the second vibration mode in planes xy and xz exists for simply supported spatial beam (tables 1-2) since its nonhomogeneous boundary conditions allow such deformation, i.e. vibration mode. When using the commercial code TOWER in this case there is no vibration mode, because TOWER uses the concentrated mass matrix, as opposed to ALIN which is using consistent mass matrix. Circular Journal of Applied Engineering Science 14(2016)1, 361

438.46

506.55

/3/-/1/

/4/-/1/

/5/-/1/

/6/-/1/

/7/-/1/

/8/-/1/

/9/-/1/

/10/-/1/

1.62

0.41

0.13

0.05

-13.13

-2.37

-1.20

-0.98

2.00

0.92

0.40

-18.41

-5.91

-3.17

2.14

1.38

-21.89

-9.76

frequency of the first, i.e. the second vibration modes in planes xy and xz of the spatial simply supported beam, using the code ALIN, is different from the exact solution by 10.99%, or 27.16%, if one uses a single finite element. If discretization of the beams into smaller segments is done, the following results are obtained. Considering the spatial simply supported beam (tables 1-2), circular frequency of the first mode in xy and xz planes obtained by ALIN is different from the exact solution by 0.39% for two finite 119

Ljiljana Â&#x17D;ugi! - Free vibration analysis of spatial frames with various boundary conditions

elements, 0.08% for three finite elements, and 0.01% for five finite elements. Using the code TOWER, the difference is -1.10%, -0.45% and -0.33%. Circular frequency of the second mode, obtained by ALIN, is different from the exact solution by 10.99% for two elements, 1.18% for three elements and 0.17% for five elements, while using TOWER the error is -4.17% for three finite elements and -1.58% for five elements. For the third mode the circular frequency obtained by ALIN is different by 23.99% for two elements, 10.99% for three elements and 0.79% for five finite elements, while when using TOWER the error is -9.71% for four finite elements and -8.12% for five elements. Therefore, when using TOWER, if one uses two finite elements for a beam there are no second and third vibration modes of the spatial simply supported beam in planes xy and xz, while when three elements are used there is no the third vibration mode, since TOWER is using concentrated mass matrix. When considering the spatial clamped-clamped beam (tables 3-4) circular frequency of the first vibration mode in xy and xz planes, obtained using ALIN, is different from the exact solution by 1.62% for two finite elements, and 0.05% if using five elements. If using TOWER, the error is -13.66% for two elements and -1.62% for five elements. Circular frequency of the second mode, obtained using ALIN, is different from the exact solution by 2% for three elements and 0.4% for five elements, while using TOWER the error is 19.49% and -4.62%. When considerting the third mode, using ALIN and four elements obtained error is 2.14%, while using five elements, the error is 1.38%. On the other hand, using TOWER and four and five elements, errors are -23.63% and -12.09%. Analysing obtained results one may notice that circular frequencies of free vibrations of considered beams using two finite elements and code ALIN are approximately correct only for the first mode (error is 0.39% for simply supported beam and 1.62% for clamped-clamped beam). Using the code TOWER and discretization of a beam into two finite elements one may notice that the circular frequency of simply supported beam is approximately exact for the first mode (error is -1.10%), while for the clamped-clamped beam obtained result is not correct, since the error is larger then 10% (13.66%). Therefore, when determining circular frequen120

cies especially for higher modes, in order to obtain more correct results, it is necessary to divide beams into as much finite elements as possible. However, since ALIN is using the consistent mass matrix, division into finite elements may be smaller (i.e. less finite elements) then when using TOWER. REFERENCES 1) Br!i" S.: Dinamika diskretnih sistema, Studentski kulturni centar, Beograd, 1998. 2) Karnovsky I., Lebed O.: Formulas for Structural Dynamics: Tables, Graphs and Solutions, McGraw-Hill, 2004. 3) Sekulovi" M.: Teorija linijskih nosa!a, Gra#evinska knjiga, Beograd, 2005. 4) TOWER 6, Uputstvo za rad sa programom, Radimpex, Beograd 5) Â&#x17D;ugi" Lj: Nelinearna analiza mostova sa kosim kablovima, doktorska disertacija, Univerzitet u Beogradu, Gra#evinski fakultet Beograd, 2009. Paper sent to revision: 04.02.2016. Paper ready for publication: 15.03.2016.

Journal of Applied Engineering Science 14(2016)1, 361

Original Scientific Paper

doi:10.5937/jaes14-10443

Paper number: 14(2016)1, 362, 121-127

CONSTRUCTION WORK TASKS DURATION: NEW METHOD OF ESTIMATION AND QUALITY CONTROL Sergei Bovteev* Saint Petersburg State Polytechnical University, Saint Petersburg, Russia Svetlana Kanyukova Saint Petersburg State Polytechnical University, Saint Petersburg, Russia Vladimir Okrepilov State Regional Centre for Standardization, Metrology and Testing, Saint Petersburg, Russia Anna Rezvaia Magadan Institute of Economics, Saint Petersburg, Russia The article considers the principles of ensuring the completion of construction projects to meet the date. The authors suggest the method of assessing the progress of the project and estimating timely completion of the project based on the application of the Schedule Timeless Index (STI) and the Schedule Progress Index (SPI). The method allows to analyze dynamically the deviation of the timing of the project for prompt adoption of effective management decisions. Key words: Planning, Project management, Performance indices, Project performance INTRODUCTION

MATERIALS AND METHODS

The modern practice of construction project execution shows that the completion date of separate projects in principle can not be delayed and ensuring timeliness of construction is an important management task. For the projects where the failure of meeting dates leads to serious, to catastrophic consequences creation of effective system of planning and control of project dates has a great meaning. The world conventional standards of project management pays great attention to project dates planning and control, in particular, in a Guide to the Project Management Body of Knowledge (PMBOKÂŽ Guide) [01] published by the Project Management Institute (PMI), in the International Competence Baseline (ICB) [02] published by the International Project Management Association (IPMA) and others [03]. At the same time these standards cover the processes of project planning in detail, however it doesnÂ&#x2019;t sufficiently state the guidelines of ensuring achievement of planned dates of separate activities and the entire project. The methodology of project management uses the term deadline as designation of date to which activity or the complex of activities or the entire project have to be completed. Failure of the deadline can be considered as project crash [04-10].

In case of the construction project crash we need to make a rule to name the achievement of such results of the project (on duration, cost, quality, scope and other parameters) which are beyond the established limit values and lead to basic failure of the project purposes [11]. If a construction project crash happens we should necessarily state what caused such results of the project (in terms of duration, cost, quality, scope and other criteria) having gone beyond the established limit values and led to basic failure of the project purposes. One of the main objectives of investigation of crashes and incidents is to prevent their emergence in the future. At implementation of construction projects it is necessary to provide timely data acquisition about the potential achievement of critical values of parameters which can lead the project to a catastrophic outcome and expeditious development of the effective administrative decisions, allowing to remove project parameters for a framework of critical conditions. For ensuring construction project to complete on time it is necessary to create the effective system of tracking and control of project dates [12, 13], one of such methods is presented below. The revisions of the construction project can be performed with the frequency equal to one week.

*Saint-Petersburg State Polytechnical University, Politekhnicheskaya, 29, Saint-Petersburg, 195251, Russia; bovteev@bk.ru

121

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

The actual project progress should be checked to the data which is called as the status date. Schedule tracking by criterion of time has to be carried out according to functionality project management software, in particular Oracle Primavera P6 [14] and Microsoft Project Professional [15]. The actual activities start and finish dates are checked daily. The parameter of the remaining duration for all performed project activities is weekly evaluated. We suppose to take a forecast of an expected date of activity finish date as an input of this parameter. Remaining Duration (RD) - the amount of time which needs to be spent of the status date for the activity completion. If the activity is performed according to the schedule, the Remaining Duration will be determined by a formula: RD = Total Duration Actual Duration (1) Otherwise it is necessary to specify the forecast finish date (FFD) of activity: FFD = Status Date + Remaining Duration (2) Here, the Remaining Duration will be determined by an expert way or on the basis of calculation depending on the type of work and it s implementation method. Before the start of the project it is important to accept a certain forecasting period, it is necessary in order to control not only those activities which are planned to be performed within the status date, and not only behind the schedule, but also the activities scheduled to start within the forecasting period (usually from 4 to 8 weeks). Thus, for activities planned within this period it is nec-

essary to specify an expected date of their start and their expected duration. The important problem of control consists of evaluation on the basis of collected and processed actual data about activities performance and an assessment of the entire project condition [16, 17]. As a result of such periodical assessment it is necessary to produce a short, laconic Project Status Report which reflect a situation for the following reporting to project stakeholders [18, 19]. The project manager and project team usually are expecting to get answers to the following key questions: If the project completion date is going to meet the deadline? If the earned project value is equal to the planned project value? The essence of an assessment of possibility of the project completion date as to the project target date is shown on curve (Figure 1). Here: Tst - start project date; Ttar - target completion project date; Tfor - forecast completion project date, depends on the achieved progress of the project, at the project start date is equal to Ttar, at the project completion date is equal to Tact; Tact - actual completion project date, when the project will be finished; !T(t) = Ttar Tfor - function of project dates deviation. The curve (Figure 1) shows that, despite existence of the negative forecast of project completion date deviations, these deviations don t leave out of the set limits (see the admissible value of deviation) and the project to be finished on time.

Figure 1: The curve of deviation of the forecast project completion date according to the status project date in case of completion project date is on time

122

Journal of Applied Engineering Science 14(2016)1, 362

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

The curve (Figure 2) shows that, the forecast of deviations from a target date of the project left out the set limits that led finally to failure of project deadline. The time point where the function of a deviation of the forecast project completion

date according to the status date exceeded the limit of admissible value, is a point of no return , i.e. it is possible to consider that further beyond this point it is impossible to bring the project back on track.

Figure 2: The curve of deviation of the forecast project completion date according the status date in case of failure of deadline of the project

RESULTS AND DISCUSSION It is necessary to consider two main tracked features to estimate the status of the entire project: timeliness of the project completion date and extent of progress of activities performing in comparison with the schedule [11]. The Schedule Timeless Index (STI) can be calculated by the following formula: (3) where Ttag - target completion date of the project is defined during the approval of the baseline; Tfor - expected completion date of the project, i.e. date of approach of a finishing milestone of the project, determined by the current schedule for status date; SD - status date. The value of the STI depends on amount of time which remains before finish of the project, i.e. to be able to make management decisions. The actual project progress can be measured as the ratio of activities which are actually completed as per the status date to amount of activities which has to be completed according to the baseline schedule. In this case the completion of activities is considered both the numerator, and the denominator i.e. if an activity is being performed now it is considered incomplete that creates a certain reserve. If project activities are Journal of Applied Engineering Science 14(2016)1, 362

equal in terms of importance, it is possible to reduce calculation of this index to a quantitative assessment: Ncompl / Nplanned, where Ncompl the amount of activities, which are actually completed as of the status date; Nplanned - the amount of activities which have to be completed as of status date according to the baseline. This index will correspond to the Schedule Performance Index (SPI) from the Earned Value Management [20- 22]. However it is necessary to consider the time which remains before the completion of the project, and also to carry out an assessment of value of a deviation of the actual parameters from planned, instead simply define a ratio of the performed and planned activities. Taking into account these factors, a relative indicator the Schedule Progress Index (SPI) - will be calculated by a formula: (4) The STI can be considered as the basic, and the SPI - as an additional. Values of these indexes aren t interconnected therefore change of one index will directly not influence the value of other. It is necessary to estimate the limit of these indexes to define in what zones the projects are in terms of time [11]. 123

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

Table 1: The example of successful implementation of the project Status Time to Plan Amount Date Completion of activities

Actual Amount of activities

Project Duration Variance

STI

STI Zone

SPI

SPI Zone

0,020

Dark green

0,414

Dark green

210

203

196

0,036

Dark green

0,214

Dark green

189

125

150

0,053

Dark green

0,222

Dark green

182

165

210

0,033

Dark green

0,315

Dark green

175

210

280

0,011

Dark green

0,400

Dark green

168

260

350

0,000

Dark green

0,433

Dark green

161

330

400

-3

-0,019

Light green

0,277

Dark green

154

400

460

-5

-0,032

Light green

0,205

Dark green

147

470

530

-4

-0,027

Light green

0,182

Dark green

140

540

600

-2

-0,167

Light green

0,167

Dark green

133

610

650

-8

-0,104

Light green

0,104

Dark green

126

720

700

-10

-0,069

Light green

0,069

Dark green

119

830

820

-7

-0,059

Light green -0,021 Dark green

112

930

950

-8

-0,071

Light green

0,040

Dark green

105

1020

1040

-10

-0,095

Light green

0,039

Dark green

112

1090

1110

-12

-0,052

Light green

0,040

Dark green

119

1160

1180

-6

-0,066

Light green

0,61

Light green

126

1230

1260

-8

-0,095

Light green

0,021

Light green

133

1300

1310

-4

-0,052

Light green -0,086 Light green

140

1390

1350

-9

-0,129

Light green -0,086 Light green

147

1500

1450

-11

-0,175

154

1620

1500

-8

161

1690

1590

168

1760

175

1820

182

189

-0,111

Yellow

-0,143

Light green -0,278

Yellow

-6

-0,122

Light green -0,254

Yellow

1670

-6

-0,143

Light green -0,256 Light green

1790

-4

-0,114

Light green -0,099 Light green

1880

1870

-3

-0,107

Light green -0,040 Light green

1930

1915

-2

-0,095

Light green -0,078 Light green

196

1960

1955

-2

-0,143

Light green -0,038 Light green

203

1980

1975

-1

-0,143

Light green -0,076 Light green

210

2000

If the STI > 0 or the SPI > 0 - project implementation is in a dark green zone. If the -0,15 < STI < 0 or the -0,5 < SPI < 0- project implementation is in a light green zone. If the -0,3 < STI < -0,15 or the -0,3 < SPI < -0,15 - project implementation is in a yellow zone. If the STI < -0,3 or the SPI < -0,3 - project implementation is in a red zone. When the value of two indicators is in a dark green zone the project implementation goes better than planned. 124

Yellow

Success

When the value of at least one of two indicators exceeds the dark green zone into the light green, it indicates that it is close to it s negative deviations from the schedule, but these deviations are insignificant and they can be neglected. When the value of at least one of two indicators exceeds the light green zone into the yellow one the schedule of the project demands recalculation. In this case it is necessary to find opportunities for acceleration of the remained activities or if it is impossible or it is inefficient, to negotiate Journal of Applied Engineering Science 14(2016)1, 362

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

agreement of moved project deadline [23-25]. In case when the value of at least one of two indexes exceeds the yellow zone into the red one - the project can be considered as failed on dates in spite of the fact that there is still time before project completion. It should be noted that the extreme value of these indexes directly depend on amount of the reserve put at the schedule evalu-

ation. If the project is carried out according to rather intense schedule which isnÂ&#x2019;t providing considerable internal reserves, extreme values of indexes have to be minimum, and vice versa. Anyway, it is necessary to approach determination of the extreme values of indexes responsibly. The example of successful implementation of the project is presented in Table 1.

Table 2: The example of failure implementation of the project Status Time to Date Completion

Plan Amount of activities

Actual Amount of activities

Project Duration Variance

STI

STI Zone

SPI

SPI Zone

210

203

0,020

Dark green

0,414

Dark green

196

0,036

Dark green

0,214

Dark green

189

125

150

0,053

Dark green

0,222

Dark green

182

165

210

0,033

Dark green

0,315

Dark green

175

210

280

0,011

Dark green

0,400

Dark green

168

260

350

0,000

Dark green

0,433

Dark green

161

330

400

-3

-0,019

Light green

0,277

Dark green

154

400

460

-5

-0,032

Light green

0,205

Dark green

147

470

530

-4

-0,027

Light green

0,182

Dark green

140

540

600

-2

-0,014

Light green

0,167

Dark green

133

610

650

-8

-0,060

Light green

0,104

Dark green

126

720

750

-10

-0,079

Light green

0,069

Dark green

119

830

820

-7

-0,059

Light green

-0,021

Dark green

112

930

950

-8

-0,071

Light green

0,040

Dark green

105

1020

1040

-10

-0,095

Light green

0,039

Light green

112

1090

1110

-12

-0,122

Light green

0,039

Light green

119

1160

1180

-6

-0,066

Light green

0,040

Yellow

126

1230

1260

-8

-0,095

Light green

0,061

Red

133

1300

1310

-4

-0,052

Light green

0,021

Red

140

1390

1350

-9

-0,129

Light green

-0,086

Red

147

1500

1450

-11

-0,175

Yellow

-0,111

Red

154

1620

1500

-15

-0,268

Yellow

-0,278

Red

161

1690

1560

-20

-0,408

Red

-0,330

Red

168

1760

1630

-20

-0,476

Red

-0,369

Red

175

1820

1680

-20

-0,571

Red

-0,462

Red

182

1880

1730

-18

-0,643

Red

-0,598

Red

189

1930

1770

-15

-0,714

Red

-0,829

Red

196

1960

1800

-13

-0,929

Red

-1,224

Red

203

1980

1840

-12

-1,714

Red

-2,121

Red

210

2000

1880

-10

Journal of Applied Engineering Science 14(2016)1, 362

Failure

125

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

CONCLUSION Herein we state a system of project parameters indication that allows to track effectively the condition of activities (a complex of activities) in particular and the entire project, as well as to provide timely information on approach of critical parameters which can lead to substantial, catastrophic effects. This method allows to make an assessment of the project progress in order to make the effective management decisions, allowing to remove project parameters from the framework of critical conditions. The proposed method can be used in the construction project management. This method can be used to ensure completion of the project or the key milestones on time. REFERENCES 1) Archibald, R.D. (2003): Managing High-Technology Programs and Projects, 3rd Edition p. 396. 2) Bovteev, S., Terentieva, E. (2014): Construction project schedule control, Projectand Program Management, No.2, pp. 158-173. 3) !etkovi" J., Rute i" S., Zarkovi" M., Kne evi" M., Vatin N. (2015): Primary directions and advancements in competitiveness of montenegrin construction sector, Procedia Engineering, 117 (1), pp. 780-790. 4) !etkovi", J., Kne evi", M., arkovi", M., Murgul, V., Vatin, N. Development and competitiveness improvement of the construction sector in Montenegro (2014) Applied Mechanics and Materials, Vols. 638-640, pp. 2465-2470. 5) Chatfield, C., Johnson, T. (2013): Microsoft Project 2013. Step by step, Redmond, Washington. 6) Chegotova, E.V. (2012): The Role of technical customer in the organization of investment activities in construction, Magazine of Civil Engineering, 29(3), pp. 5-11. 7) Heldman, K. (2009): PMP: Project Management Professional Exam study Guide, 5th Edition, p. 677. 8) Homutinnikova, K. C. (2009): Evaluation Criteria methods of verification used in managing construction projects, Management projects and programs, No.4, pp. 312-323. 9) ICB IPMA Competence Baseline (2006): Version 3.0. Nijkerk, The Netherlands. 126

10) L.Lynch. (2010): On Time and under budget: a project management method critical chain (2010) pp. 354. 11) Project Management Body of Knowledge (2012): 5th ed. Project Management Institute. Newtown Square, Pennsylvania. 12) Project Management in Construction. Fourth Edition. pp. 285. 13) Ptukhina, I.S. (2011): Methodology of the distribution of economic justice the perpetrators for the delay of completion, Kuban state agrarian University, 04(68), pp. 383-394. 14) Pukhkal, V., Murgul, V., Garifullin, M. (2015): Reconstruction of Buildings with a Superstructure Mansard: Options to Reduce Energy Intensity of Buildings, Procedia Engineering, Vol. 117, pp. 624-627. 15) Rute i" S., !etkovi" J., Kne evi" M., arckovi" M., Vatin N. (2015): Institutional framework, current investments and future strategic direction for development of construction sector in Montenegro, Procedia Engineering, 117 (1), pp. 642-650. 16) Rute i" S., !etkovi" J., arckovi" M., Kne evi" M., Vatin N. (2015): Analysis of the situation in montenegrin civil engineering sector from the point of application of national regulations and the EU technical standards in construction, Procedia Engineering, 117 (1), pp. 905-915. 17) Schlagbauer, D., Heck, D. (2013): Change in output performance due to prolonged work, ISEC 2013 - 7th International Structural Engineering and Construction Conference: New Developments in Structural Engineering and Construction, pp. 1375-1380. 18) Suetin, S.N., Titov, S.A. (2014): Project portfolio management: strategic level of project management, Economy and Entrepreneurship, 5-2 (46-2), pp. 509-515. 19) Vatin, N.I., Kolosova, N.B., Berdyugin, I.A. (2013): Efficiency of application of automatic control systems, accugrade in construction, Construction of Unique Buildings and Structures, 4 (9), pp. 29-35. 20) W. Lipke. (2012): Earned schedule contribution to project management, PM World Journal, Vol. 1, Issue 2. 21) Werkl, M, Heck, D. (2011): Coping with incompleteness: An approach using time and production related compensation, ISEC Journal of Applied Engineering Science 14(2016)1, 362

Sergei Bovteev - Construction work tasks duration:New method of estimation and quality control

22) - 6th International Structural Engineering and Construction Conference: Modern Methods and Advances in Structural Engineering and Construction, pp. 279-284. 23) Williams, D.L. Krazer, E.B. (2012): Oracle Primavera P6 Version 8: Project and Portfolio Management: A comprehensive Guide to managing projects, resources, and portfolios using Primavera P6, through version 8.2. Birmingham & Mumbai: PACKT Publishing. 24) Yakovlev, Y.V. (2010): Mechanisms of management of complex investment and con-

Journal of Applied Engineering Science 14(2016)1, 362

struction project, Moscow: Creative house. 25) Yu. N. (2008): Lapygin Project management: from planning to evaluation, Moscow: Omega-L, p. 252. 26) Zakieva, N.M., Sirazetdinov, R.M. (2011): Corporate project management system as management mechanism of innovative projects in investment-construction complex, News of the Kazan, No.3, pp. 211-218. Paper sent to revision: 07.02.2016. Paper ready for publication: 10.03.2016.

127

Original Scientific Paper

doi:10.5937/jaes14-10450

Paper number: 14(2016)1, 363, 128 - 134

USAGE OF ZINC-SILICATE COATINGS IN FRICTION CONNECTIONS Nenad Fric* University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Dragan Bu"evac University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Zoran MiÂ&#x161;kovi" University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Zlatko Markovi" University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Jelena Dobri" University of Belgrade, Faculty of Civil Engineering, Belgrade, Serbia Usage of zinc-silicate coatings as anti-corrosive protection of friction connections results in reduction of construction time and provides protection from corrosion. Such protection system has a number of advantages in respect to the widely implemented metallization procedure, prevalently in terms of speed of implementation, required training of the workforce and cost. In this paper were presented friction coefficients for different systems of anti-corrosive protection of friction connections, with emphasis on the zinc-silicate coatings and their technical characteristics and implementation methods. Key words : Zinc-silicate coating, Friction coefficient, Friction joint connections, SRPS, Eurocode INTRODUCTION In the procedure of selection of anti-corrosive protection of friction surfaces, apart from the required corrosion resistance, another very important factor, and often a conclusive one, is the required friction coefficient between the elements (steel plates) connected with pre-stressed bolts. The slipping force does not prevalently depend on the friction between the surfaces in contact, but on the shearing of bulges on those surfaces [1]. From this point of view, it would be the best to leave the structure without anti-corrosive protection, that is, to connect the structural elements immediately after sandblasting. It is generally known that high friction coefficients are attained in cases of steel surfaces treated by sandblasting. However, in most of the cases this is not feasible, either because of the time required for fitting of the steel structure (long enough for the corrosion process to start developing on the sandblasted elements) or because of inability to seal the constructed friction joint connection in such a way to prevent exposure to oxygen and thus prevent corrosion development.

For these reasons, the friction surfaces must be protected from the corrosive actions, and consequently, the fiction coefficient created in them by the implemented protection system must be determined. This procedure is standardized, considering the fact that it is often conducted. In the Republic of Serbia, the friction coefficient of the friction surfaces is determined using SRPS U.E7.140:1985 standard [02]. Since 2012, the standard SRPS EN 1090-2:2012 [03] is simultaneously valid, so this procedure, with slight modifications, is harmonized with the procedure implemented in the European Union. By implementing these standards, a large number of experiments was conducted which accomplished categorization of the anti-corrosive protection systems according to the attained friction coefficients. Usage of zinc-silicate coatings as anti-corrosive protection of friction surfaces results in reduction of construction time and provides adequate protection from corrosion. Such protection system has a number of advantages in respect to the widely implemented metallization procedure, prevalently in terms of speed of implementation,

*Faculty of Civil Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, Belgrade, Serbia; fric@imk.grf.bg.ac.rs

128

Nenad Fric - Usage of zinc-silicate coatings in friction connections

required training of the workforce and cost. Even though implementation of protection systems of friction surfaces based on coatings has a very long tradition in the world, it was practically implemented in Serbia for the first time in 2011, during reconstruction of the Â&#x201E;GazelaÂ&#x201C; bridge in Belgrade. The reason for this are difficulties in procurement of the adequate coating and traditional recommendations for implementation of metallization procedure on the friction surfaces. This procedure comprises application of a certain alloy on the friction surface. The most frequently used alloy is one of aluminum and magnesium AlMg5. Metallization certainly results in high friction coefficients, but on the other hand requires adequate equipment (metallizing gun), consumption of gas and metal wire, skilled workforce, adequate protective equipment and sealing of the joints after fitting of bolts (most often by

using putty) for preventing exposure to oxygen. The emergence of coatings, which simultaneously provide a satisfactory friction coefficient, caused the decrease in use of metallization process. By standardization of testing, the determination of friction in friction joints is facilitated and standardized. Regarding the continuous development of the anti-corrosion systems industry, which places a large number of coatings on the market, the determination of their characteristics for use in friction joints is considerably simplified. The values of friction coefficient were defined by SRPS standard [02] (Table 1) for various levels of treatment and systems for protection of friction joints from corrosion. In case of EN standards [3] the classes of friction surfaces are defined, and the friction coefficients which must be attained for each of them. (Table 2).

Table 1. Friction coefficients for various methods of treatment of friction joints surfaces, according to SRPS standard [02]

The method of treatment of contact (friction) surfaces Without a special treatment Cleansing by fire Unprotected Sandblasted Sandblasted surfaces subsequently protected by coating of aluminum alloy Protected

! S235 0,30 0,40 0,50 0,50

S355 0,30 0,40 0,55 0,50

Table 2: Friction coefficients for various methods of treatment of friction joints surfaces, according to EN standard [03] Surface treatment

Class

Surfaces blasted with shot or grit with loose rust removed, not pitted

0,5

Surfaces blasted with shot or grit: 1. spray-metallized with a aluminium or zinc based product; 2. with alkali-zinc silicate paint with a thickness of 50 !m to 80 !m

0,4

Surfaces cleaned by wire-brushing or flame cleaning, rust removed

0,3

Surfaces as rolled

0,2

From the enclosed tables, it can be clearly seen that the contemporary regulations have a more conservative approach to these issues and that they prescribe lower friction coefficients. Also, the contemporary regulations recognize zinc-silicate coatings as a form of anti-corrosive protection of friction surfaces as opposed to the national regulations adopted thirty years ago (1985) which were, until recently, the only binding regulations in the Republic of Serbia.

Journal of Applied Engineering Science 14(2016)1, 363

FRICTION COEFFICIENTS FOR VARIOUS SYSTEMS OF PROTECTION OF FRICTION JOINTS FROM CORROSION The friction coefficients for unprotected friction surfaces, friction surfaces protected by classic anti-corrosive protection, and the surfaces protected by zinc rich ethyl-silicate coating will be presented through two referential researches. These values are significant for analysis of adequacy of zinc-silicate coatings implementation.

129

Nenad Fric - Usage of zinc-silicate coatings in friction connections

In his doctoral dissertation, Vlaji! [01] experimentally, using standardized procedures, determined friction coefficients on the friction surfaces protected by: - metallization using aluminum and magnesium alloy AlMg5, - metallization using pure aluminum, - classic anti-corrosion protection (chlorine primer manufactured by Zorka abac), - chlorine primer coating with addition of silicon carbide (or carborundum) SiC. In addition, for the purpose of comparison, in the same research was determined friction coefficient on the surfaces without anti-corrosive protection, for two different levels of treatment: by sandblasting and by polishing. The initial idea was to improve the characteristics of classic anti-corrosive protection and increase the friction coefficient by adding silicon carbide, which would make it applicable in friction joints. Silicon carbide belongs to inorganic compounds with extremely high toughness and relatively low

production cost. For this reason, it became widely used in industry, especially for production of sandpapers, abrasive materials and similar. The author conducted an extensive experimental research (a total of 260 specimens) and determined friction coefficients (table 3) with small standard deviations, which confirms quality and reliability of this experimental research. The obtained values for the surfaces treated by sandblasting and metallization are considerably higher than those defined by Eurocode which makes experimental determination of friction coefficients for the purposes of construction of structures increasingly important. By adding carborundum to the classical coatings, friction coefficient was increased for more than 30%, which justified this procedure. It was concluded that better results could be achieved by applying carborundum on only one friction surface. In this way, crushing of the grains in mutual contact at the moment when the bolts are being tightened would be prevented.

Table 3: Friction coefficients for various methods of treatment of friction areas Vlaji [01] Steel grade Surface treatment

S235

Standard deviation [%]

Number of samples

sandblasting

0,616

4,30

sandblasting + metallization (AlMg5)

0,548

5,20

188

sandblasting + metallization (Al)

0,363

7,80

sandblasting + hlorvenmijum + SiC

0,308

2,44

sandblasting + hlorvenmijum

0,235

8,82

polishing

0,156

6,80

Wylliam Husson in the research which is the integral part of his thesis [4], among other things, determined friction coefficients on the surfaces treated in two ways: - steel plates of S355 class, sand blasted to Sa2,5 level, in all according to the standard ISO-8501-1 [5], subsequently coated with two-component zinc rich ethyl silicate coating TEMASIL 90 , manufactured by Tikkurila Coatings , - weathering steel plates with commercial name COR-TEN B [6] manufactured by Ruukki , in the first batch sand blasted and immediately tightened with bolts, and in the second batch sandblasted and exposed to weather effects prior to tightening.

130

Friction coeff. "

The coating, used during research, has already been widely used in construction of wind turbines and it can be used as a single coating, or as a primer in a complex system of anti-corrosion protection. In both cases it is applied in a layer of 50 µm to 80 µm with the zinc content ranging between 70 and 90%. Weathering steel contains elements allowing formation of patina in the event of exposure to weather effects. A number of samples was formed from the plates which did not exhibit rust, and the remaining number from the plates exposed to weather effects which were fitted among the samples after formation of patina. The product COR-TEN B , according to its mechanical properties corresponds to the steel of the S355J0W(P) class. Journal of Applied Engineering Science 14(2016)1, 363

Nenad Fric - Usage of zinc-silicate coatings in friction connections

The friction coefficients presented in Table 4 were determined for formed specimens. It is important to point out that the friction coefficients

prescribed for the class B of friction surfaces were not attained on the samples protected by zinc rich coating.

Table 4: Friction coeff. for various methods of treatment of friction surfaces Husson [04]

Steel grade Cor-Ten B Cor-Ten B Cor-Ten B S355

Surface treatment Friction coeff. ! sandblasting 0,591 sandblasting + atmospherics 0,629 sandblasting + atmospherics 0,611 sandblasting + Temasil 90 0,310

ZINC-SILICATE COATING RESIST 86 MANUFACTURED BY JOTUN Zinc-silicate coating Resist 86 (manufactured by Jotun , Norway) as anti-corrosive protection of friction surfaces of the Gazela bridge was selected assuming that the friction coefficient higher than 0,4 can be achieved between two steel plates protected by this system. This is simultaneously the first implementation of zincsilicate coatings on the friction surfaces in the Republic of Serbia. It was the first time (2010) that the value of friction coefficients which can be used on friction surfaces with this system of anti-corrosion protection applied was determined for the bridge reconstruction purposes [07]. The procedure of determination of friction coefficient was conducted in all according to the provisions of the SRPS U.E7.140:1985 standard [02]. TECHNICAL CHARACTERISTICS AND METHOD OF APPLICATION OF ZINC-SILICATE COATING RESIST 86 This system of anti-corrosive protection was designed by the manufacturer [8] for heavy duty corrosion protection system, both: - as the primer (first layer) in multi-layered systems, or - as a single-layer coating for protection of steel surfaces in medium-to-severe corrosive environments. It is a two component, fast curing, zinc rich ethylsilicate coating. It consists of component A and powdery component B (dry zinc dust) which are mixed in the ratio A : B = 8 : 2,6. Component A must be well shaken before use, since sediment is bound to settle while it is still. It is very important to pay heed to the fact that the liquid component A has a limited shelf life, which is 6 months stored in dry and dark place at a temperature of 23 ºC. Exposure to higher temperatures Journal of Applied Engineering Science 14(2016)1, 363

Number of samples 3 3 5 17

shortens the expiry time and causes conversion of liquid into a jelly. Because of these facts, implementation of zinc-silicate coating, Resist 86 , especially in summer season, calls for a careful planning both in practical application and in conducting of experimental research. The manufacturer prescribes minimal, maximal and optimal coating thickness (Table 5). It is particularly stressed that if the film thickness exceeds 120 µm there is a high probability that the film would crack . Table 5. Prescribed coating film thickness in wet and dry states [08] Film thickness [µm]

Film condition

Minimum

Maximum

Typical

Dry

Wet

135

115

After the completed cleaning using sandblasting, dust is removed from the cleaned surfaces using compressed air of manually using brushes, which completes the preparations for application of anti-corrosive protection. In the course of application of zinc-silicate coating, it is necessary that the substrate temperature is no less than 5ºC, but also no less than 3 ºC above the dew point. In principle, curing of the zinc-silicate coatings requires moisture. At low relative humidity of air, curing is increased by sprinkling of coating film with fresh water or by artificial increasing of the environment humidity (Figure 1a). In order to create a desired thickness in dry state, the coating thickness in wet state (immediately after application) was measured, using wet paint comb gauge (Figure 1b and 1c). Each of the coating application techniques, either using compressor or manual, requires continuous stirring in order to avoid settling of the heavy zinc particles, which is a fast developing 131

Nenad Fric - Usage of zinc-silicate coatings in friction connections

process. At the moment of application of any of two layers of anti-corrosion protection, the weather conditions must be in accordance with

the conditions prescribe by the manufacturers, which is measured on the site and registered in the log book.

b) a) c) Figure 1: a) Spraying of film with fresh water in low humidity conditions; b) and c) Measuring of the coating thickness in wet state [09]

FRICTION COEFFICIENTS IN CASE OF IMPLEMENTATION OF ZINC-SILICATE COATING RESIST 86 The fact the zinc-silicate coating Resist 86 never before was used for friction joints, called for an extensive experimental research aimed at determining of friction coefficient. Friction coefficient was determined by testing of a total of 48 specimens, and a particular emphasis was placed on analysis of the impact of time interval between the application of coating and tightening of the bolts, for the attained friction coefficients. The test [07] was divided in two parts. The first, where the tightening of the bolts and testing of the specimens took place at the same moment one after another, and the second part where the samples were tested after a certain time passed since the bolts had been tightened. The initial tests demonstrated that in a short time period after application of the coating (up to 3 days) it is not possible to attain the required friction coefficient. The obtained friction coefficients of 0,29 to 0,38, but also a prominent dissipation of results, indicated the need to perform tests after a longer time period since the moment of application of the coating. Accordingly, the tests were performed 6, 8 and 10 days since the moment of application of the coating, on 4 specimens for each time period. The attained friction coefficients were between 0,46 and 0,50 but there was also a standard deviation of less than 8 % which is within the permissible boundaries 132

according to the standard. The obtained results certainly justified implementation of Resist 86 coating in the friction surfaces of the Gazela bridge, but they raised the question of technology and duration of construction regarding the anti-corrosive protection of friction surfaces. Since it was a reconstruction of the existing bridge structure, it was conducted in phases, and it was very important to provide restoration of the prefabricated elements of the bridge (plates and bolts) into the original state in as short time as possible after their dismantling. For that reason, a third part of this research was conducted, where the friction coefficients were determined 10 days after application of the coating, and tightening of the bolts to the full torque was accomplished 72 h after application of the coating. The obtained results allowed improvement of technology of reconstruction of the bridge construction and considerable shortening of time required for works on the anti-corrosive protection. The bolt tightening 72h after application of the coating and loading of the structure 10 days after that yielded the best results, i.e. the best friction coefficients between 0,49 and 0,50. Following the made conclusions, the contractor developed of a system of supporting the platess using a long grub screws (Figure 2). In this way, it was made possible to tighten the bolts 72 h after application of the coating. After tightening of all the joints, more than ten days passed until they were exposed to service loads. Journal of Applied Engineering Science 14(2016)1, 363

Nenad Fric - Usage of zinc-silicate coatings in friction connections

Figure 2: Reconstruction of the Gazela bridge in Belgrade implementation of zinc-silicate coating Resist 86 as anti-corrosive protection of friction surfaces [09]

CONCLUSION

REFERENCES

Implementation of zinc-silicate coatings represents an efficient way of anti-corrosive protection of friction surfaces. The main precondition for them to substitute the metallization procedure is attainment of required friction coefficients in friction joints. However, the required friction coefficients for the surface treatment category A and B, according to Eurocode, !"0,4 and !"0,50 respectively, cannot be attained with any zinc-silicate coating. Because of that, it is important, prior to implementation of coating in the friction joints, to determine friction coefficient which can be attained. In the case of zinc-silicate coating Resist 86 manufactured by Jotun the best results are achieved by tightening the bolts 72 h after applying the coating and by loading the structure 10 days after that, which was confirmed by the experimental research for the purposes of reconstruction of the Gazela bridge in Belgrade. Such system of protection of friction surfaces, applied in the described way, provided good results and facilitated shortening of time needed for application of anti-corrosive protection. Certainly, technology of bridge construction differs from their reconstruction, in terms of dynamics. Therefore, it will be useful to determine friction coefficients for longer period between application of the coating on the steel structure elements, bolt tightening and exposing those elements to service loads. By following the analogy of the presented results of experimental researches, it can be expected that the attained friction coefficients will be even higher, i.e. more favorable from the aspect of slipping resistance of the joints.

1) Lj. Vlaji#: Pona anje spojeva sa visokovrednim zavrtnjevima pri eksploatacionom i grani$nom optere#enju , Doktorska disertacija, Univerzitet u Ni u, 1993, 122 str. 2) SRPS U.E7.140:1985: Spojevi sa vijcima visoke klase $vrsto#e kod nose#ih $eli$nih konstrukcija - Tehni$ki uslovi , 1985. 3) SRPS EN 1090-2:2012: Execution of steel structures and aluminium structures Part 2: Technical requ for the execution of steel structures , Institute for standardization of Serbia, 2012. 4) W. Husson: Friction Connections with Slotted Holes for Wind Towers , Licentiate Theses, Luleå University of Technology, 2008, 192p. 5) ISO 8501-1:2007: Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings , International organization for standardization, 1998. 6) Hot-rolled weather resistant COR-TEN, http://www.ruukki.com/Steel/Steel-products/ Hot-rolled-steels/Hot-rolled-weather-resistant-COR-TEN, dostupno 30. septembra 2014., 17:30 7) GP Mostogradnja AD, Vlajkovi#eva 19a, Biro za kontrolu kvaliteta, Laboratorija za ispitivanje: Izve taji o ispitivanju koeficijenta trenja µ tarnog spoja pritegnutog V.V. vijc-

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ima, pripremljenog po sistemu RESIST 86 (Jotun), april-jun 2010. Godine , Beograd. 8) Jotun Norway: Technical data sheet for Resist 86 , http://wwwda.jotun.com/jotun/ paints/20020020.nsf/wvwProductDatabase/ F89C5FE225EEC6CEC12568F500261088/ $file/TDS%20-%20Resist%2086%20%20English%20(uk)%20-%20Issued.11.06.2012.pdf, dostupno 11. Oktobra 2013., 18:30

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9) N. Fric: Teorijsko i eksperimentalno istra ivanje gubitaka sile prednaprezanja u visokovrednim zavrtnjevima , Doktorska disertacija, Gra!evinski fakultet Univerziteta u Beogradu, 2015, 305 str. Paper sent to revision: 01.02.2016. Paper ready for publication: 07.03.2016.

Journal of Applied Engineering Science 14(2016)1, 363

Original Scientific Paper

doi:10.5937/jaes14-10455

Paper number: 14(2016)1, 364, 135-139

EFFECT OF GOODWILL ON THE PERFORMANCE OF THE ORGANIZATION OF THE CONSTRUCTION SECTOR Vladimir Okrepilov* State Regional Centre for Standardization, Metrology and Testing in St. Petersburg, Russia Marina Gravit Saint Petersburg State Polytechnical University, Saint Petersburg, Russia Ekaterina Nedviga State Regional Centre for Standardization, Metrology and Testing, Saint Petersburg, Russia Dudnik Oleg Magadan Institute of Economics, Saint Petersburg, Russia There are issues of Goodwill and reputation risk. Particular attention is paid to the development of national standards for the evaluation of the experience and reputation of organizations. It is described the justification of creating the standard for evaluation of the experience and reputation of the building organizations. There is the method of valuation of goodwill, intangible assets that evaluates construction company. The methodology includes five factors, each of which includes some subfactors. The assessment according to this method of Russian standard 56002-2014 Evaluation of experience and reputation building organizations the construction company will be assigned a code of business reputation. Key words: Business reputation, Assessment methodology, Construction INTRODUCTION Nowadays, standardization not only develops and is an independent tool for ensuring quality and safety. There is a new vision of objects of standardization: one of them as products and services, as well as other intangible stakeholders - namely goodwill enterprise. In April 2013, in the Russian Federation published the Federal Law ! 44-FZ (ed. by 07.13.2015) On the contract system in the area of procurement of goods, works and services for state and municipal needs , according to which (par. 2, Art. 31) The Government of the Russian Federation the right to establish parties to procurement of certain goods, services ... additional requirements, including the presence of goodwill [1]. In Russian Federation also discussed the draft federal law On the construction contracts for state and municipal needs, as well as the needs of the individual legal entities , a feature of which is that it pointed to the need to ensure access to works construction contracts only to qualified contractors to meet their obligations and to provide the necessary indicators of

quality, reliability and security. A key mechanism for the selection of qualified contractors is the procedure of qualification assessment, carried out by the self-regulatory organizations. Federal law On self-regulatory organizations given the right to self-regulatory organizations to develop standards themselves in order to eliminate factors that create unfair competition [02]. It is necessary to define the concept of goodwill , standardize, identify it correctly according to the developed criteria to evaluate proxy authentication and therefore be able to reduce the reputational risks for the enterprise. The difficulty lies in the fact that goodwill organization - complex characteristic, multi-faceted and complex to identify and evaluate. Directly or indirectly the market takes part in its formation [30 - 12]. GOODWILL AND METHODS OF EVALUATION Western companies have long estimated goodwill enterprises (goodwill), the concept of goodwill first appeared because of trade and finance and actively used in the Middle Ages in various

*State Regional Centre for Standardization, Metrology and Testing in St. Petersburg and Leningrad Region (State Centre Test-St. Petersburg ), Kurlyandskaya, 1, St. Petersburg, 190103, Russia; letter@rustest.spb.ru

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trade unions. Currently, the most approximate to this aspect of the standards for the evaluation of goodwill standards are the ISO technical committee TC 289 Assessment of the brand , as well as ISO standard 10668: 2010. Brand valuation - requirements for monetary brand valuation («Brand valuation - Requirements for financial valuation of the brand ) [10 - 13]. The term goodwill in Russia until recently was used exclusively as accounting and banking terms. For each organization in the Russian Federation has the goodwill attached article. 150 of the Civil Code Russia intangible benefits , and the object of evaluation can only serve as goodwill, set on the balance sheet. In the balance of this magnitude occurs when the company was purchased another enterprise and the cost of their own goodwill in the balance sheet is not reflected [14]. In regulatory documents, scientific and methodical literature, there is no one-valued interpretation of the concept of goodwill [03 - 15]. According to the Russian Accounting Regulations Intangible Assets Accounting (PBU 14/2007) [15]), the goodwill recorded in intangible assets, as well as works of art inventions and trademarks, and is defined as the difference between the purchase price of the company (value of property complex as a whole) and the carrying value of all its assets and liabilities. Goodwill organizations should be considered as a premium paid by the buyer in anticipation of future economic benefits, and to take into account as a separate inventory item of intangible assets. Negative goodwill in full refers to the company s financial results as other income in the full amount [15]. The rules laid down in [15], the accounting for negative goodwill close to the International Financial Reporting Standards (IFRS) [14, 16, 17]. Therefore, goodwill is a set of assets that encourage customers to use the products and services of the given company. Negative goodwill (asset value) may be the lack of stable customers, poor product quality, lack of marketing skills, low-skilled personnel, lawsuits, precedent to the manufacture of counterfeit products. Obviously, the importance of correct assessment of the reputation is especially great in the provision of services, where the cost of goodwill is significant value along with an assessment of tangible assets in determining the value of a business. There are two approaches for the assessment of 136

reputation: quantitative and qualitative. In practice most widely methods are method of excess profits; assessment of goodwill, based on the volume of sales index; qualimetric method and others. The qualitative approach include a method of sociological surveys and expert method, the followers of which are of the opinion that to calculate the exact amount of goodwill can t be, and can only fix it change - for the worse or better. Currently existing methods for determining the value of goodwill of the company are not universal. The function according to the value of goodwill on the level of innovation of the company can be represented by the formula Cr = f (Ki, D, IR, mass media, M, Esin) where Cr - amount of goodwill (goodwill); Ki - factors indicating the effect on Cr enterprise products (price of products, quality, production time and other work.); D - market share of the enterprise; IR - innovative development of the enterprise; Media - the influence of the mass media (coverage of the enterprise); M - marketing policy of the enterprise (promotional activities, the creation of a web site and its support and so on.); Esin - a synergistic effect on innovation and marketing development [18]. In conjunction with marketing activities and taking into account the influence of media goodwill could increase significantly under the influence necessarily resulting synergies. In the present situation the companies are given the opportunity to establish itself as the innovative development of enterprises and improve business reputation [10 - 13]. Changing the goodwill, maintaining it at a certain level, and improve the software associated with the concept of reputational risk. Reputation risk - a set of risks resulting from the company and related to improper use of the brand, poor production of goods and services, the failure of the relevant laws, as well as the damage caused to its reputation, which threatens us in the future to lose the trust of customers, employees, shareholders, partners and other stakeholders. Reputation should be viewed as a source of risk both in itself and as a result of interaction with other types of risks. Therefore, reputational risk is a comprehensive risk [14, 16]. Obviously, there is reputational risk for businesses of all types, Journal of Applied Engineering Science 14(2016)1, 364

Vladimir Okrepilov - Effect of goodwill on the performance on the organitzation of the construction sector

so it is important to be able to identify, describe, analyze, assess its quality, and to make recommendations for managing them. Market assessment of reputation and associated risk now in Russia is not developed. This is due to the lack of clear formal valuation models and lack of reliable information about companies [7, 10, 12, 13, 16, 17], as well as the absence of rules and regulations and the definition of counterfeit means of combating it [14]. So, according to [1], the Government of the Russian Federation the right to establish parties to purchases additional requirements, including the availability of business reputation. For the construction industry in Russia, the state order is the foundation of financial stability. The share purchases in the public procurement market amounts to 60% of all the ongoing tender procedures, while the market itself is far from equilibrium. The majority of construction companies - are companies that operate on the market for over 5 years, and their work is reduced to search of lucrative contracts and their implementation with the maximum benefit for themselves without regard to future orders, developed and approved by an adequate system of assessment of the experience and reputation is designed to reduce risks to market procurement of unscrupulous contractors.

of subfactors with the established weight and a specific range of the evaluation (Figure 1): - Factor History includes subfactors number of years in the market and the rhythm of implementation ; - Factor Means includes subfactors material base , financial autonomy , construction in progress ; - Factor Personnel includes subfactors managerial skills , middle tier , awards and titles ; - Factor Prestige includes subfactors citation , elimination of violations , delayed delivery of objects , Emergencies , certified management system , customer feedback ; - Factor Credibility is a multiplier of all the factors in the model and has a default value of 1.

EVALUATIVE FACTORS OF INTANGIBLE ASSETS In 2014, the national standard Rosstandart approved a new Russian standard 56002-2014 Evaluation of experience and reputation building organizations , which is designed Profit Partnership The National Center for the dedicated , JSC Institute of goodwill , JSC All-Russian Research Institute certification , made by the Technical Committee for Standardization TC 066 Assessment of experience and business reputation and establishes general requirements and criteria for evaluating models goodwill construction companies on the basis of their work experience. The standard contains the procedure for expert evaluation, evaluation model of business reputation and a number of applications, including the method of estimating the goodwill of a construction company [19]. The standard will evaluate the intangible assets on the basis of this technique, which operates five factors, each of which includes a number Journal of Applied Engineering Science 14(2016)1, 364

Figure 1: Evaluative factors of intangible assets of companies

The evaluation according to Russian standard 56002-2014 construction company is assigned an index of goodwill in the range from 0 to 1. When the index is less than 0.5 the certificate of conformity is not issued a construction company, as evidenced by the extremely low level of business reputation. The highest index range - 0.8 - 1.0 get market leaders [20]. In order to be an independent evaluation process, it adopted a proposal to establish a reputation in the Commission for Standardization Technical Committee 066 Evaluation of experience and business reputation enterprises (hereinafter - the Commission). A commission with the participation of concerned government bodies and professional associations, but the main principle of selection of representatives should be impeccable professional reputation and author137

Vladimir Okrepilov - Effect of goodwill on the performance on the organitzation of the construction sector

ity of specific expertise in the relevant field of activity. The Commission was established to improve the competitiveness of Russian business through the development of reputation-oriented approach to business, and ensure the credibility of estimates conducted by the standards developed by Technical Committee 066. The main task of the commission will be ensure the credibility of the standards being developed to assess the experience and reputation in different industries, and the performance of the functions of impartiality, facilitate the development of a system to assess the experience and reputation of organizations of various sectors and the credibility of the assessment [23-28]. In 2015, we developed the following new standards: Russian standard 66.0.01-2015 Evaluation of the experience and reputation of businesses. The national system of standards. General provisions, requirements and guidelines ; Russian standard 66.1.01-2015 Evaluation of the experience and reputation of businesses. The national system of standards. Evaluation of the experience and reputation of persons carrying out architectural and construction design ; Russian standard 66.1.02-2015 Evaluation of the experience and reputation of businesses. The national system of standards. Evaluation of the experience and reputation of persons carrying out engineering surveys . Therefore, the rating indicator provides an opportunity to get enough objective information about the terms of the company s reputation and helps to determine the strengths of the company and potential growth points. Finally, the public indicator of success is not only financial, but also the professional development of the company allows you to compare the level of development of the company and its competitors, as well as to adequately position itself in the market. An important factor is the universal assessment of the reliability of data provided by a participant ranking [3, 10 - 12, 21, 22]. CONCLUSION The federal legislation includes such requirements as having the experience and reputation, but no system of recommendations that would allow the customer to navigate among the offerings on the market of goods and services. Evaluation of the experience and reputation can be carried out rating, because it achieved sufficient 138

accuracy at a relatively low cost. The objectivity of the study will be based on expert opinion reputational Commission organized on a voluntary basis and made up of the most representative of industry experts. For the construction industry, it is means that there will be easier access to the construction works of skilled contractors able to meet its obligations and to provide the necessary indicators of quality, reliability and security. At the same time the system will transition to a complex procurement model, which is based will lie quality and safety. REFERENCES 1) Law ! 44-FZ About contractual system in the procurement of goods, works and services for state and municipal needs , Collection of Laws of the Russian Federation. 2) Law ! 315-FZ The self-regulatory organizations Collection of Laws of the Russian Federation. 3) Titova, V.A., Tomilina, Y.V., Titova, T.V. (2014): Information technology in the system of purchasing decision-making based on models of long-term and short-term marketing actions , 9th International Forum on Strategic Technology, IFOST 2014, art. no. 6991111, pp. 234-237. 4) Dunning, D., Anderson, J.E., Schlösser, T., Ehlebracht, D., Fetchenhauer, D (2014): Trust at zero acquaintance: More a matter of respect than expectation of reward , Journal of Personality and Social Psychology, 107 (1), pp. 122-141. 5) Kuzheleva-Sagan, I.P., Suchkova, N.A. (2015): Designing trust in the Internet services AI and Society, p. 12. 6) Abitov, I.R. (2015): The distinctive features of a picture of the world of the students of pharmaceutical faculty , Review of European Studies, 7 (5), pp. 47-51. 7) KyuJin Shima, Sung-Un Yangb (2015): The effect of bad reputation: The occurrence of crisis, corporate social responsibility, and perceptions of hypocrisy and attitudes toward a company , Public Relations Review, In Press. 8) Slabá, M., tarcho", P., Já# I (2014): Identification and prioritization of key Stakeholder groups in marketing communication of colleges , E a M: Ekonomie a Management, 17 (4), pp. 101-110. 9) Höglund K., Wennerström M. (2015): When the Going Gets Tough Monitoring Missions Journal of Applied Engineering Science 14(2016)1, 364

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and a Changing Conflict Environment in Sri Lanka 2002 2008 , Small Wars and Insurgencies, 26 (5), pp. 836-860. 10) Mindrut, S., Manolica, A., Roman, C.T. (2015): Building Brands Identity , Procedia Economics and Finance, Vol. 20, pp. 393 403. 11) Gurianov, P.: Dividend policy and major shareholding profitability , Metallurgical and Mining Industry, 7 (7), 2015, pp. 101-106. 12) Gardini, S., Grossi, G. (2014): Voluntary adoption of the consolidated financial statement and fair value accounting by Italian local governments , Journal of Public Budgeting, Accounting and Financial Management, 26 (2), pp. 313-344. 13) Schiemann, F., Richter, K., Günther, T.: The relationship between recognised intangible assets and voluntary intellectual capital disclosure , Journal of Applied Accounting Research, 16 (2), 2015, pp. 240-264. 14) Gravit, M.V., Krivoshonok, V.V. (2015): Standardization as an instrument for combating counterfeiting, and improve business reputation of organizations engaged in entrepreneurial activity in the field of fire safety , Fire safety, ! 4, pp. 47 - 52. 15) Approval of Accounting Regulations Intangible Assets Accounting (PBU 14/2007) an order from the Russian Ministry of Finance on December 27, 2007, ! 153n. Registered in the Russian Ministry of Justice on January 23. 2008 ! 10975, Rossiyskaya Gazeta, N 22, 02.02.2008. 16) Zobkova, J.O., Pakhomov, A.V., Pakhomov, E.A. (2008): An integrated approach to assessing the business reputation of the enterprise , Mathematics. Computer. Education, Coll. works of the XV International Conference. Edited by GU Riznichenko Izhevsk: Research and Publishing Center Regular and chaotic dynamics , Vol. 1, pp. 150-153. 17) [Makarov, E.I., Dyakonova, S.N. (2012): The dependence of the business reputation of the enterprise innovation development level , Creative Economy, ! 7 (67), pp. 119-124. 18) Shlafman, A.I. (2009): Theoretical Foundations of business regulation , Russian Entrepreneurship, vol. 1 (126), pp. 25-29. 19) Shakhov, V.: Standard Confidence , The world of security, ! 1, 2015, "". 62 -63. 20) Suprunchuk, D.S. (2015): The performer s reputation. On providing a standardized approach to the evaluation of experience and reputation Journal of Applied Engineering Science 14(2016)1, 364

party procurement as one of the criteria for nonad valorem , billyuteney TC 001. For the measurement of goodwill, ! 1, "". 38 44. 21) Zadorozhko, D.S. (2013): Modern approaches to the evaluation of goodwill and reputation risk , Management of economic systems: an electronic scientific journal, ! 8(56), ".34. 22) Urbanaviciene, V., Kaklauskas, A., Zavadskas, E.K., Sliogeriene, J., Naimaviciene, J., Vatin N.I. (2014): Facilitating the housing bargaining with the help of the bargaining decision support system , International Journal of Strategic Property Management, 18 (3), pp. 213-224. 23) #etkovi$, J., Kne evi$, M., arkovi$, M., Murgul, V., Vatin, N. Development and competitiveness improvement of the construction sector in Montenegro (2014) Applied Mechanics and Materials, Vols. 638-640, pp. 2465-2470. 24) #etkovi$ J., Rute i$ S., Zarkovi$ M., Kne evi$ M., Vatin N. (2015): Primary directions and advancements in competitiveness of montenegrin construction sector, Procedia Engineering, 117 (1), pp. 780-790. 25) Rute i$ S., #etkovi$ J., arckovi$ M., Kne evi$ M., Vatin N. (2015): Analysis of the situation in montenegrin civil engineering sector from the point of application of national regulations and the EU technical standards in construction, Procedia Engineering, 117 (1), pp. 905-915. 26) Rute i$ S., #etkovi$ J., Kne evi$ M., arckovi$ M., Vatin N. (2015): Institutional framework, current investments and future strategic direction for development of construction sector in Montenegro, Procedia Engineering, 117 (1), pp. 642-650. 27) Jevri$ M., Kne evi$ M., Kalezi$ J., Kopitovi$ Vukovi$ N., #iprani$ I. (2014): Application of fractal geometry in urban pattern design [Primjena fraktalne geometrije u projektiranju gradskog obrasca] Tehnicki Vjesnik, 21 (4), pp. 873-879. 28) Lazarevska M., Knezevic M., Cvetkovska M., Trombeva Gavriloska A. (2014): Application of artificial neural networks in civil engineering [Primjena umjetnih neuronskih mre a u gra%evinarstvu] Tehnicki Vjesnik, 21 (6), pp. 1353-1359. Paper sent to revision: 29.01.2016. Paper ready for publication: 14.03.2016.

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Original Scientific Paper

Paper number: 14(2016)1, 365, 140 - 147

doi:10.5937/jaes14-10528

LIGHT REVEALING ARCHITECTURE FORM - THE ROLE OF LIGHT IN CONTEMPORARY INTERPOLATION Sanja Paunovi!- ari!* University of Montenegro, Faculty of Architecture, Podgorica, Montenegro Veljko Radulovi! University of Montenegro, Faculty of Architecture, Podgorica, Montenegro Ema Alihod i!-Ja arovi! University of Montenegro, Faculty of Architecture, Podgorica, Montenegro Vera Murgul St. Petersburg State Polytechnical University, Saint-Petersburg, Russia The paper provides an overview of the role of light (both daily and artificial) in façade treatment on the examples of contemporary interpolations. Design of façade envelope with regard to the characteristics of light (natural and artificial) ranges from the response to natural elements of the context, via treatment of light as substance, the role of light in constructing and transforming architecture, the role of light in attracting attention, to the communicative and interactive role of light in media towns. The use of classical elements has been analysed and transposition of traditional or natural language has been indicated, as universal response to the conditions of locality, by transforming their formal possibilities using new technological achievements. It has been shown that such architecture may be well interpolated and returned to the place, related to the events in space, and it may contribute to the change of image of our towns, in general. Key words: Light as a material, Facade, Interpolation, Media facades, Daylight INTRODUCTION The form of a town is first of all the expression of historical and physical continuity [Radovi!, 2009]. The uniqueness and authenticity of architecture, which represent the accumulation of everything composing genius loci and zeitgeist in which it occurs, stem from the viewpoint that architecture may be examined only in relation to the context of its historical development. Therefore, urban past should represent the preparation for entrance into the future. Town is an organism not resistant to various diseases and today they are almost incurable. Town is never final and completed, but an active organism susceptible to permanent alterations. We architects have to do our best so that the spaces of life of citizens make functional, cosy, human-oriented and imaginative. In this way, we would return the depts to the spaces of our living [Kolacio, 1978]. Urban growth, encouraged by the strength of global economic power, significantly influences the change of urban identity, which considerably conditions the sustainability of the town and traces its future development di-

rections [Alihodzic Jasarovic, E, 2015]. The level of randomness of a newly made architecture has been noticed, leading to the architecture outcast from the context and directed towards its destruction and negation. Such desaturation does not mean that we will leave intangible or unordered spaces. Building should be carried out so that new functional and aesthetic combinations may endlessly enrich by conserving, establish by preserving, protect life heritage by not reducing the town to a museum or monumental cemetery, what has always been included in the town, but what it will never be [Derrida, 1992]. It is not easy to develop architecture within the existing developed urban fabric. Disregarding hermetic viewpoint related to history and historical heritage as dominant and appreciating the needs of the town for further development and extension, there is a question of how to perform new articulation of space by the means of light, and solves requests based on the preservation of compositional artistic qualities, which represent the sedimentation of cultural historical trends.

*Faculty of Architecture, University of Montenegro, Podgorica, Montenegro; paunovicsanja@gmail.com

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ROLE OF CONTEMPORARY INTERPOLATIONS IN URBAN CONTEXT Interpolation process or the process of integration of urban events, as well as regularly defined physical architectural interpolation simultaneous and parallel strategies of urbanism system, simultaneously contributes to the construction of a town [Mrdulja , 2011]. Interpolation appears as the most active type of urban recovery, and it has been made from French word interpoler , which means: to embed insert a new building into the already existing historical urban unit, which then becomes aesthetic veneer of newly built structures. According to Bernard Tschumi, in order to achieve harmonious and aesthetically appropriate building in historical surrounding, it is necessary to explore the relationship among: concept, context and content [Tschumi, 2005]. This relationship may move from indifference, reciprocity to absolute conflict, so it is suggested to architects to direct their activity more towards research and materialization of concept, rather than towards the shaping. Stratification and complexity of historical urban context should be one of key factors taken into consideration during contemporary interpolations in space. Quality parameters and legitimacy of interpolation which influence urban form and typology of heritage, as well as the lessons for contemporary design have been considered through the following [Idrizbegovi!-Zgoni!, 2009]: 1) Valorization of the existing: objective valorization (building/structure has to have rational relationship towards natural, climate and morphological conditions, create functionally rational and useful space and activate surrounding space as integral part of the building) and subjective valorization (it estimates the value of the valued and defines author s personal affinity towards certain ambience); 2) Identification with space attempt of an author to reach the core of spatial relationships in the ambience. Building/structure visually and aesthetically has to create quality relationships with environment in measures, proportion, volumes and materials by creating continuity, emphasizing the existing characteristics of the space. Immediate contact of historical context and newly designed building has been frequently solved via: harmonization of rhythm of façade apertures, materiJournal of Applied Engineering Science 14(2016)1, 365

als, masses, volumes, structural grids, style harmonization, transposition and the like; 3) Ownership of expression manner of expression or the language of shapes has to be in line with the time of building, as architecture is the reflection of its time. It has to represent generator of innovativeness and positive universal characteristics of architecture. Interpolated building/structure has to comply with metaphysical aspects of the context (memories of a place, ambience ) and use phenomenology during the design of a space. DESIGN OF BUILDING ENVELOPE AS THE INTERPOLATION ELEMENT The era of technology and application of new materials very frequently radically breaks ties with tradition, place and identity. Architecture has radically transformed its formal possibilities by technological progress and design of new programmes which enable the calculations of complex structures and forms. In the mid-nineties, new ways of digital production of images and simulation of objects influenced also the manner of expression in architecture, which transforms architectural image into event. As such, architecture has started to break ties with the spirit of place, while stratification and complexity of historical context have become neglected. Technology tends to standardize architecture, make it uniform, which results in globalization of architectural thought. Accordingly, the nature of contemporary architecture is not characterized by adapting to historical urban context, so such new buildings/structures are frequently in opposite relationship with context, ignoring and confronting it. The root of the word façade is related to Latin word facies (face). Façade represents the face of the building and the component by which the building is most directly identified. Contemporary architecture is increasingly oriented towards the treatment of façade shell as independent element, by adding multi-layer element into the meaning and functions. Façade does not represent the border anymore, which closes certain volume, but it represents the tie between the nature, environment, building and interior volume ["ukovi! Ignjatovi!, 2010]. The number and multi-layer element of functions undertaken by the façade, technical characteristics it encom141

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passes, additional complex meanings and interpretations intertwined with these processes, require critical view of physical, functional and symbolic border of the façade, and aperture in general. New technologies, materials and their possibilities in use provided encouraging motive to architecture, as conceptual programmes may ensure their existence in future . Observing the envelope of the building as the element of building interior with the environment both in technical and semantic terms, as one-of-a-kind envelope which, in contemporary architecture, represents a complex system which defines and articulates the mentioned topics in layers [Ugljen Ademovi!, 2012]. The envelope of the building, by development of contemporary technological solutions, has been treated as independent element with regard to the building structure, so its role is of paramount importance in contemporary interpolations. Design of façade envelope with regard to the characteristics of light (natural and artificial) ranges from the response to natural elements of the context, via treatment of light: as substance, the role of light in constructing and transforming architecture, the role of light in attracting attention, to the communicative and interactive role of light in media towns. Unlike numerous examples of mega sculptures, the examples of fetish abstraction, breaking ties with continuity of the place, correct treatment of façade shell may contribute that the space be experienced through all senses, emphasizing emotional character of the building and harmony between façade envelope and impression of built space, by the means of light. THE LIGHT IS SHAPING ARCHITECTURE This chapter analyses natural light, pointing at formal solution of natural light and its benefits, and develops the architectural concept whereas the form follows the Sun shaping itself depending on local climate parameters. All climate parameters applicable to topography are also valid for the existing urban fabric, thus according to Frampton [Foster, 1983], the building must be designed considering unpredictable climate and weather characteristics of sunlight at a given location, which the sensitive modulation and incorporation of such factors must almost by definition be fundamentally opposed to the optimum use of universal technique. This is perhaps most clear in the case of light and climate control. The generic window is obviously the most delicate 142

point at which these two natural forces impinge upon the outer membrane of the building, fenestration having an innate capacity to inscribe architecture with the character of a region and hence to express the place in which the work is situated [Foster, 1983]. Nowadays the most comfortable and pleasant spaces are those that allow the designer and users to establish control over the lighting. Such spaces wherein the object of interest is adequately emphasized by adjusting the source of light will be freed from visual discomfort, and the need to introduce artificial light will be minimized. The genesis of design principle the form follows the Sun is shown in the examples in Figures 1-3. With trapezoids windows Breuer managed to control light intrusion in the interior volume subject to the complexity of museum exhibition lighting. Using the form of inverted ziggurat without openings, the building is entirely closing towards the Sun (Figure 1, a)). The development of glazing materials and excessive solar radiation protection systems enabled the architect to shape the object and open it towards the Sun. Multitude of dynamic visures of façade surfaces and uneven height arrangement of volumes, together with the Sun, make that the Sun turns the game of light and shade into the key element that reveals the distribution and shape of building s monolete volumes. Volumes are covered with metal grids, which act as light filters, where the light is refracted and gives the façade a shimmering outlook. (Figure 1, b)). Angular fins in aluminum frames on the sides of the windows stick out from reinforced concrete structure. They have been threedimensionally designed as to provide protection from negative solar radiation, overheating and precipitation [dezeen.com] (Figure 1, c)). The project of the extension of Tate Modern museum in London has achieved complementary dialogue with the existing historical context, by emphasizing the existing, by balance in tactile material, architecture which returns the impulse to touch . Herzog & de Meuron architects have avoided shocking interventions which would alter the image of the town. They tried to harmonize the new building with original aesthetics and artistic values of the original building. Correct disposition of apertures on the façade encourages symbolic value and discovers uniqueness and attractiveness of the form. This example illustrates that the significance of the tactile is found in the fact that it may be decoded only in Journal of Applied Engineering Science 14(2016)1, 365

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terms of the experience: it may not be reduced to mere information, to representation or simple

apparent evocations which change the absence of presence [Foster,1983].

Figure 1: a) 1966: Whitney Museum - Marcel Breuer, New York, USA, b) 2007: New Museum of Contemporary Art - Sanna, New York, USA, c) 2013: KURO Building - KINO Architects, Tokyo, Japan

Figure 2: Proposal design for expansion of Tate Modern museum to officially open in 2016 - Herzog & de Meuron, London, UK

Figure 3: Light defined as a material a) Dome of the Pantheon, b) Le Corbusier s chapel at Ronchamp, c) Chapel Klaus, Pater Zumthor

THE LIGHT IS CREATING AN ATMOSPHERE OF ARCHITECTURE Architecture is the masterly, correct and magnificent play of masses brought together in light. Our eyes are made to see forms in light; light Journal of Applied Engineering Science 14(2016)1, 365

and shade reveal these forms; cubes, cones, spheres, cylinders or pyramids are the great primary forms which light reveals to advantage; the image of these is distinct and tangible within us without ambiguity. It is for this reason that these are beautiful forms, the most beautiful forms 143

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[Le Corbusier, 1923]. Architecture is determined by light. The light reveals the architectural form and meaning, making it distinctive and universal. Light should be understood as substance We could say that traditional or classic architecture has been always insisting on the durability of architectural design. More and more we try to work with concepts such as programming of complex architectural effects on the same building. Playing with transparency always implies playing with material, so that the building could have multiple faces . If we work with glass, it is possible to programme what we will see [Mrdulja , 2008]. Dome of the Pantheon - a sophisticated lighting effects emphasize form (Figure 3, a)), Le Corbusier s chapel at Ronchamp - light emphasizes haphazard arrangement of windows forming a matrix and emphasizing the mass (Figure 3, b)), Chapel Klaus, Pater Zumthor the play of light and materials, light emphasizes texture (Figure 3, c)) [16]. Transforming architecture by the means of artificial light, the emotional experience of the observer could be falsified thus making the architectural identity of the building more complex. Skillful combination of colour and artificial light could affect the relationship building observer, in the following ways: 1) the colour of the light arouses emotions in the observer, emphasizing and enhancing architecture, falsifying emotions in the object viewer relationship; 2) the lighting makes the architectural concept adjustable allowing a 24-hour life of the object and its interaction with the environment; 3) the lighting substitutes classical façades with new experiences, emphasizing the play of colours and giving the completely new night outlook to the neutral building shell; 4) it emphasizes the tactility and functioning like an extension of the sense of sight, the eye like a sense of touch operating at a distance [zumtobel.com/façade]; 5) the dynamic nature of lighting and intensive colours make the object perceived from a distance, attracts attention and observer s desire to explore it or communicate with it. Light can affect the emotional experience and attract the attention. Coloristic culture is a name for a phenomenon which bares emotional, aesthetic and semantic information (Also known as 144

synesthesia - union of the senses ). Transformation of town spaces by the introduction of coloured structures is one of the ways to express expert attitude towards public town space. Transformation of the condition of a certain monochromatic environment into a polychromatic one may be best understood in the context of its development [Vasiljevi! Tomi!, 2007]. Radical intervention of transformation of form i.e. structure has been recognized on the example of the Museum of Modern Art in Malmö (Figure 4). Extension of the museum was designed so as to emphasize the arrival new museum contents, to represent a rare opportunity for the creation of new nodes within constructed town structures and to transpose the materialization of industrial brick of nearby buildings into the sheath of highest climate and security performances. The alignment of colour with historical urban context, the achievement of coloristic and volumetric harmony, ensured the conditions for the creation of spatial values: intelligibility, emotionality and behavior [Vasiljevi! Tomi!, 2007]. In the pursuit for coloristic harmony of town ambience, it may be talked about monochromatic interventions for the sake of achieving coexistence of the new and the inherited. These interventions imply the preservation of values of historical urban context. One and the same colour, which has appropriate physical characteristics, evokes different feeling [Idrizbegovi!-Zgoni!, 2009]. In the example of the headquarters of Dolce & Gabbana company in Milan (Figure 4 [16]), coloristic harmonization of space has resulted in the increase of quality of town ambience, by complying with spatial and social requirements. Entirely modern ode to classicism has managed to contribute to aesthetic expression and pleasant psychological climate, by fostering sophisticated and recognizable style. The simplicity of architectural details, economic transparent materials which make the building transparent and extrovert, both during the day and during the night - by the use of neutral light tones, may be considered a good formula for successful interpolations in historical urban contexts.

Journal of Applied Engineering Science 14(2016)1, 365

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Figure 4: a) 2009: Moderna Museet Malmö - Tham & Videgård Arkitekter, Malmo, Sweden, b) 2006: Dolce & Gabbana Headquarters - Studio Piuarch, Milan, Italy

Achievements in the development of technologies and materials have encouraged architects in their conceptual programmes, so they have found a model for architectural works to exist during the night, by insisting on their dual nature and recognisability: during the day by interesting volume, during the night by light-transparent façade. Owing to the development of LED technologies, façade is now able to exist unobtrusively during the day, while during the night, when it is not possible to view urban environment, it is transformed into new spatial values. The permanence of change in the example of

Museum of Art in the town of Celle (Fig. 5 [18]) may be interpreted almost physically, while the light integrated into the envelope of the building may be read as its second skin . The first 24hour museum in the world offers the concept of incessant art , in which visitor becomes the part of interactive scenario. This building respects both apparently opposite principles: respect the evolution of timeless values and sensations as a mirror of the moment [Ugljen Ademovi!, 2012], respecting three main parameters of the form: dynamic, structure and meaning.

Figure 5: 2006: Museum of Art - Ahrens Grabenhorst Architekten BDA Hannover

INTEGRATIVE ROLE OF LIGHT IN ARCHITECTURE Media façades are defined as surfaces, envelopes or membranes where the integrated visual electronic programme functions as the public media . The Latin origin of the word has the meaning of convertibility, flexibility and reaction to external influences (mediaarchitecture. org). The role of façade as the media is based on four characteristics: interactivity, multimedia, connectivity and generativity [a-theory.tuwien. Journal of Applied Engineering Science 14(2016)1, 365

ac.at]. These types of facades have a tendency to transform experience into new forms. Media days are endless, and the present is subject to commercial contents. Auto-active and interactive video contents filter the content of marketing facilities and influence the perception of a passerby. Today artificial lighting is vital for the society because it has been exploited as a medium for launching social transformations [Derrida, 1986]. The award-winning and socially recognized author of Croatian architectural practice, Kre imir Rogina, in his article From a Visual Civilization 145

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to an Audio Tactile Culture (Original title: Arhitektonski fokus Kre imira Rogine (Iz vizuelne civilizacije k audio taktilnoj kulturi) states that architecture in digital age is definitely no longer the play of volumes in the light, but the play of digital information in space [Rogina, 2011]. Hypermultimedial buildings provide information by means of communication with the environment reconciling the schizophrenic ambivalence of physical and virtual reality. Buildings are identified with billboards, and while sound and light sensations occur in the structure of the building s envelope, the space inside of the volume becomes almost unadaptable for dwelling. New virtual city spaces disrupt the intimacy and render false aspirations of the social community. The narrative structure of traditional building envelopes now becomes an autonomous element that allows

us to be in many places at the same time. The city becomes the scene for urban interactions of media façades, the place for virtual dialogue. Façades are treated like building land and collective action place. The relationship between the passer-by and envelope is no longer only physical and visual, but the place for emotional focus and interactive drama. These urban decorations cannot be treated as architectural solutions. Large screens (billboards) are not aimed at cultural and artistic awareness, but acquire strictly commercial characteristics, and become the means for demonstrating the power of gigantic corporations. Outdoor cinemas, large displays are treated like real estate, relocating the issues of everyday life into cyberspace. They represent the source of light pollution that is the product of light illuminations in cities.

Figure 6: a) Times Square 1904 before the era of media façades, b) Times Square during the day, c) Times Square during the night [19]

In the 2000 Charter of Zurich interactivity was classified into nine points of new architecture . Interactivity is defined as: closely related to the development of new intelligent materials, not only responding to the environmental conditions but also conditioning their structural changes and adjustments [Rogina, 2011]. The fact that cities like New York are considered media cities is truly justifiable. Reference points in such cities are no longer defined by streets, corners and squares, but by media façades or ensemble of buildings designed in the spirit of media technology. This type of public spaces replaced the former public spaces with classic aesthetics, becoming the spaces of permanent circulation, so it appears like the implemented screens are competing to attract more attention and acquire a dominant position in the sound and colour drama. Cities like New York and Tokyo now speaks, it emotes, at night as in the day [Lefebvre, 2004]. Buildings expand into infinity, with only one aim, to provide more space for marketing activities. Buildings 146

and their aesthetic characteristics are not perceived due to their covering with screens, so the interpolation in such urban contexts is based on the level of screen layering. CONCLUSION Is there any successful model which guarantees a quality compromise? As stated at the beginning, the only idea is that tradition phenomenon is accepted as unchangeable situation, while the content made by the method of replication, citation and transcription is the only one considered as successful. Usually in pursuit for timeless solutions, we turn to past, seeking for the solutions in tested historical images. Such approach reflects the burden of the past, and it may rather easily lead to dual adversity: the past and tradition are treated as static phenomena deprived of development and frozen in certain moment, or provisional interpretation of heritage is created, indulged to utterly subjective attitude of the author, which frequently leads to misunderstandJournal of Applied Engineering Science 14(2016)1, 365

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ing [Petrovi!, Ra kovi!, 2011]. On the other hand, the idea is that completely new spatial and visual forms, established for the first time in a visual environment, should express the values in time they occur, as well as be their trace of future. Diversity of built contents which make the whole illustrates the situation described by Geoffrey Bennington as the paradox of the future of the past by which the rules of creating a unit are established during its creation, so that the work has a character of event [Bennington, 1984]. Bernard Tschumi in his text Architecture and Transgression says the following: Architecture of pleasure is found where concept and experience of space abruptly coincide, where architectural fragments collide and merge into ecstasy, where architectural culture is endlessly deconstructed, and all the rules are breached. There is no metaphoric end, only uneasiness and misbalance of expectations. It denies everything typologies, morphologies, spatial compressions, logical constructions [Tschumi, 2005]. The acceptance of such concept requests the appreciation of mutual relations through their differences, for what it is necessary to establish new way of thinking, suitable to today s cultural moment. We find codes in spatial experience, which represent nothing else by spatialization of time, which are exactly the old historical town centres. REFERENCES 1) Alihodzic Jasarovic, E., Komatina, D., Paunovi! ari!, S., Murgul, V., Vatin, N. (2015): Decentralization as a cause of spatial segregation, Applied Mechanics and Materials, Vols. 725-726, pp 1134-1140. 2) Bennington, G., Massumi, B. (1984): Racionalnost revitaliteta postmoderne, Minneapolis: University of Minnesota Press. 3) Derrida, J. (1992): Générations d une ville: mémoire, prophétie, responsabilité , Éditions de l Aube. 4) Foster, H. (1983): The Anti-Aesthetic essays on postmodern culture (Kenneth Frampton: Toward a Critical Regionalism: Six Points for an Architecture of resistance), Buy Press, New York. 5) Idrizbegovi!-Zgoni!, A. 2009: Challenge of set frames, University of Trieste, Italy. 6) Kolacio, Z. (1978): Vizije i ostvarenja, Zagreb. Journal of Applied Engineering Science 14(2016)1, 365

7) Le Corbusier, (1923): Vers une architecture, Paris 8) Lefebvre, H. (2004): Rhythmanalysis Space, Time and Everyday life, Continuum, New York, pp. 46 9) Mrdulja , M. (2008): Singularni objekti athitektura i filozofija, Birotisak doo, Zagreb 10) Radovic, R. (2009): Forma grada. Osnove, teorija i praksa, Gra"evinska knjiga, Beograd. 11) Rogina, K. (2011): Arhitektonski fokus Kre imira Rogine (Iz vizuelne civilizacije k audio taktilnoj kulturi), Meandar Media, Hrvatska 12) Tschumi, B. (2005): Event - Cities 3 (Concept vs. Context vs. Content), MIT Press 13) Ugljen Ademovi!, N. (2012): Kritika stimulans arhitektonskoj ideji, Dobra knjiga, Sarajevo 14) www.mediaarchitecture.org/conf/253/ (retrieved on November 22th, 2015) 15) www.a-theory.tuwien.ac.at/Profiles/Oliver (retrieved on November 22th, 2015) 16) www.zumtobel.com/façade (retrieved on November 22th, 2015) 17) www.archdaily.com (retrieved on November 22th, 2015) 18) www.kunst.celle.de (retrieved on November 22th, 2015) 19) www.presseportal.de/pm/62409/1093987/ celle-z-hlt-zu-den-12-besten-in-der-republik (retrieved on November 22th, 2015) 20) https://playingintheworldgame.wordpress. com/2012/09/17/ (retrieved on November 22th, 2015) Paper sent to revision: 03.02.2016. Paper ready for publication: 08.03.2016.

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Original Scientific Paper

doi:10.5937/jaes14-10468

Paper number: 14(2016)1, 366, 148 - 153

ACHIEVING GENDER EQUALITY IN EDUCATION IN CIVIL ENGINEERING IN MONTENEGRO Mladen Perazi!* Chamber of Economy of Montenegro, Podgorica, Montenegro Nevenka Pavli"i# Clinical Center of Podgorica, Podgorica, Montenegro Milo Kne evi# University of Montenegro, Faculty of Civil Engineering, Podgorica, Montenegro Achieving gender equality in the process of education is a long procedure which resulted in the fact that the level of education of women in Montenegro has long been equated with the level of education of men. Thus, equal gender opportunities in employment should come as a result of such situation. However, data show that women are failing, as much as men, to ensure a successful career. In recent years, the situation in education in civil engineering has been changed for the better, and in this sense the women occupy an appropriate position in this field of economy. Key words: Education, Equality, Civil engineering INTRODUCTION Education is the process where people develop their abilities and skills for life and work. It prepares the individuals for inclusion into society and gives them the opportunity for positioning in the world of work and in the community. Education is a constant process of achieving spiritual values which continues during the course of life through the activities of informal, non-formal and formal education. The influence of education process on the shaping of personality and the whole society is an immeasurable factor in development of the country. Transformation and changes in education are the reflection of changes in the society, because education is a driving force of development and one of the main factors that influence the forming of values in society. Achieving the gender equality in the process of education is a long procedure which resulted in the fact that the level of education of women in Montenegro has long been equated with the level of education of men. Equal gender opportunities in employment should come as a result of such situation, given that education is defined as the most important factor of vertical mobility and as powerful instrument for prevention of social exclusion. However, the data show that women fail to provide high quality employment and successful careers to the same extent as men. Women are still on the margins of the mainstream of society. The cause and outcome

of that is an unequal distribution of powers and the rights they have. All this leads to the keeping of traditional culture, negative aspects of patriarchal culture and further economic underdevelopment of society. Given that women represent more than 51% of the population of Montenegro, the importance of proper education of this part of population is of the key importance for the development of human resources, and thus of the national economy. Valuable and cultural system of a country, the culture of a learning society, the efforts to create the knowledge economy, are the basic infrastructural precondition for the growth, development and creation of a society which is worthy of a man. The condition for the creation of a learning society is the recruitment of all possible stakeholders in the society, especially women who represent 51.6% of the total population of Montenegro, what is more than a half in all countries of the world. In modern education systems the impartiality, the standards of values of knowledge, achievements and capabilities of individuals are respected, regardless of the gender. Modern development implies that the knowledge is the basis of social and economic growth, and education leads to the knowledge. In this respect, education is the solid foundation and the support of each country. The educational level of the population is an inevitable factor of the level of social development of a community.

*Chamber Economy of Montenegro, Novaka Milo eva 29/II, Podgorica, Montenegro; mperazic@pkcg.org

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EDUCATION AND SOCIETY Insufficient involvement of women in education throughout history has resulted in a huge nonuse of human resources potentials. Thus, if we define education as a socio-historical phenomenon and activity which represents a conscious and continuous aspiration of the community to qualify its members for tasks that are put before society and individuals, the target that all members of society are involved in this process was achieved during the 20th century. H. Gudjons [01], states that education means: - training for rational self-determination, - development of entities in the media and the objectification of previous human culture, - productive participation in culture, - achievement of individuality and sociability, - generally valid, i.e. equally valid education for all people, - versatility - moral, cognitive, aesthetic and practical dimension. Learning and education processes were present throughout the whole history of mankind, and as society evolved, these processes were becoming more complex and organized. The first teachers were women who were transferring their knowledge to descendants. Nowadays, new knowledge and education systems which are adapted to each person are needed for the survival of civilization and society. Without education every society would degrade, and people would become uncivilized and they would imperil the survival of resources on the planet by their demographic growth. P. Gazivoda points out that the preservation and usage of natural resources can only be provided with a huge investment of knowledge and capabilities of all inhabitants of our planet and that only education is able to come to an effective and lasting solutions to the issues regarding dignity of man and woman, as well as the conditions of their existence [02]. The existence of man, the preservation of the planet, the rational use of resources is closely linked to raising the level of education of the population. Thus, prof. D.M. Savi!evi!, PhD, notes that the modern world is characterized by a high degree of interdependence in the areas of economy, politics, technology, science and culture, and education is an area of a spiritual activity where such interdependence is particularly evident [3]. Qualities such as humanity, empathy, communication Journal of Applied Engineering Science 14(2016)1, 366

skills and vocational education are developed through the process of education. In the market competition of modern economy, the countries are trying to organizationally develop these qualities in its citizens through educational systems. The process and result are integrated into education which stands out. Bojan K. Lazarevi! is recognized in almost all spheres of human activity and, as such, by itself, assumes an essential element of development of an individual, no matter from which aspect it is observed [04]. The research has found that there is a high degree of correlation between an increased level of education and economic growth of the country. Educational institutions and educational level of the population does not affect only the creation of human capital, but also the strengthening of social capital. Still, women represent more than a half of the social capital in every society. However, as the environment is increasingly changing, education of the workforce should be a continuous process, since a large number of people with outdated diplomas are not the basis for economic growth. The practice of transition countries showed that women were more flexible and more willing to learn and acquire new knowledge and they easily find their place in the labor market. What is the scope of an impact of education on gender relations and womenÂ&#x2019;s emancipation nowadays points out also ". Â&#x160;uÂ&#x161;nji!, who finds that a reasonable (and human) education system must meet the following five conditions: To convey the cultural heritage and traditions to the young generation, to prepare young people to take over some of the existing working roles, to create value awareness or conscience of young people, to develop the capabilities of each individual, to develop a relationship of educational system toward the exceptional and gifted persons and geniuses. Importance of developing value awareness of education is the foundation of later attitude towards the emancipation and professional accomplishment of women. Zhou Nanzhao points out that the role of education and culture is the development which aims to flourishing of human potential worldwide [4]. N. Muji! explains the role of the educational systems at the present time stating that new demands are set before the educational systems: focusing of education on the purpose, openness of the education system, continuity of education, education outside schools, social responsibility of education. The Report of the UNESCO International 149

Mladen Perazi -Achieving gender equality in education in civil engineering in Montenegro

Commission on the Development of Education for the Twenty-first Century highlights that education is at the heart of the development of both individuals and communities, its mission is to enable each of us, without exception, to fully develop all of our talents and to achieve our creative potential, including responsibility for the personal lives and achievement of personal goals. [5] It is also stated that, in dealing with the many challenges that are waiting for us in the future, the humankind sees in education an indispensable wellbeing in the attempt to achieve the ideals of peace, freedom and social justice [06]. In the knowledge economy, education primarily promotes social inclusion of all individuals and develops their skills in order to increase their employability. An inclusion of all individuals and social groups is emphasized in order to promote their rights. Employability represents the competitiveness of knowledge, skills and abilities of individuals in the labor market. Employability is acquired by constant modernization of existing knowledge and skills and by further education, thus making easier to find a new job. J. Denison believes that an efficient education system enables training of enough people to vital skills in order to adequately contribute to economic growth in a new industrial society. At the same time the system must provide an opportunity for those in the workplace to improve their skills and fill their intellectual competitiveness in order to adapt to changes in technology [07]. This is very important as it allows a woman to reconcile her career with a role in the family and to improve her skills by flexible ways of constant trainings. Versatile and flexible offer of educational services aims to better meet the changing and heterogeneous demand. In addition to schools, various education institutions for adults are engaged for this purpose, provided that they meet the criteria in terms of quality of education. In the world, the market of educational services is very developed [08]. THE WAY TOWARDS EQUAL OPPORTUNITIES FOR EDUCATION IN MONTENEGRO As well as the in other European countries, the development path of achieving gender equality in Montenegro has been long and difficult. The period after World War II in Montenegro was followed by great social, political and economic changes. There was a massive urbanization and 150

emancipation of rural areas and populations, as well as general industrialization. These changes greatly affected the lives, rights and status of women in society. WomenÂ&#x2019;s rights were legalized by the legislation which encouraged emancipation and equality with men. In the first Constitution of the Federal Republic of Yugoslavia (FNRY) in 1946, women were formally granted the right to vote. Article 24 states that, all citizens, regardless of gender, ethnicity, race, religion, level of education, place of residence and who are over 18, have the right to elect and to be elected to all bodies of state power. In a new system women have succeeded, within the new ideology, to actively transform relations between the sexes, to establish the equality. All international conventions referring to the status of women were incorporated in the former Yugoslav legislation. Regardless of progressive legal solutions and the establishment of kindergartens and child care centers, female role of a mother and primary educator of children, as well as of one who takes care of the house and chores, was never really challenged. Following the end of World War II the most dynamic period of development of education in Montenegro begins. The Law on Primary Education, adopted in 1959, required the compulsory attendance of primary school by male and female citizens who were 7 to 15 years old. When it comes to high schools, the big problem was the lack of a developed network of schools for vocational education. Because of the patriarchal system of values the parents are unwilling to send their female children out of the place of residence. The number of women who enrolled the colleges and faculties increased in proportion to the enlarged number of faculties and colleges. Women mostly enroll teaching faculties, while a smaller number enroll the law, economics, etc. After the disintegration of FNRY the status of women has got worse. The economic crisis, the disintegration of Yugoslavia, the fall of socialism and the transition processes, they all have had negative consequences for women in Montenegro, returning them to the framework of their biological role - mother, but also to the private area - house. WomenÂ&#x2019;s role has been downgraded to the one that is dominant in patriarchal societies and the equality that socialist women won and gained was rapidly forgotten and annulled except in the education segment where they have experienced the greatest emancipation. The implementation of the concept of equality in Journal of Applied Engineering Science 14(2016)1, 366

Mladen Perazi!-Achieving gender equality in education in civil engineering in Montenegro

education in Montenegro has led, in the past 50 years, to the fact that there is no difference in the rate of enrollment of boys and girls in primary school (98.4% of boys and 98% of girls attend primary school), so at the primary level of education the gender inequality has been practically eliminated. The differences in education between men and women do not exist even in respect of secondary education. At higher levels of education, the trend of increasing participation of young women has been developed where the percentage of female students even exceeds the percentage of male students, but this advantage is lost at postgraduate studies. Given that the civil engineering and tourism are strategic sectors in Montenegro, one cannot fail to notice that an issue of deficiency is the most obvious problem in these sectors because they make over half of the demand for workforce by employers, as well as the fact that foreign workers are mostly being employed. As regards the qualification of III level of education there is a deficiency of: carpenters, masons, reinforcing iron workers, construction machinery operators, pavers, insulation workers, plasterers, facade plasterers, tilers and installers of floors, while at the qualification of IV level of education an issue

of deficiency is dominant in construction technicians, then surveying technicians, technicians for the civil engineering construction and building construction, as well as building surveyors. As regards the qualification of VII level of education, graduated engineers of geodesy are the most needed, then the engineers of architecture and civil engineers. This is supported by the fact that the geodesy and architecture started to work as independent programs merely since 2006 in Montenegro. ACHIEVING GENDER EQUALITY IN EDUCATION IN CIVIL ENGINEERING The equal right to education and equal access to education are the basis for the achievement of equal opportunities for professional career and for the realization of personal potentials of both men and women. These rights in Montenegro are guaranteed at all levels of education. There are no differences in schools and school subjects that are available for girls and boys. The legislation has no gender discriminatory provisions in the laws governing education, but there is no specific gender sensitivity, not in terms of the content of school curricula or regarding the language.

Table 1: The percentage of students in the total number of primary and high schools in Montenegro Students Schools

Classes

Finished school year

Total

Female students

Total

Female students

Regular primary education 1)

435

3318

70222

33896

8426

4104

Regular secondary education 2)

1140

31388

15 515

8447

4066

Source: Statistical Office of Montenegro, Statistical Yearbook of Montenegro 2012

Table 2: Regular male/female students in high schools High schools (I - IV) School year

Primary schools (1- IV)

Gender distribution%

Total

girls

boys

girls

boys

2009/2010

31 643

15 626

1 607

49,4

50,6

2010/2011

32 126

15 632

16 494

48,7

51,3

2011/2012

31914

15633

16281

49,0

51,0

2012/2013

31 858

15 584

16 274

48,9

51,1

Source: Ministry of Human and Minority Rights of Montenegro and Statistical Office of Montenegro (2014), Women and Men in Montenegro

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Table 3: Enrolled male/female students (undergraduate studies) School year

Total

Women

Men

2009/2010

21 199

11 268

2010/2011

22 163

11 748

Gender distribution% women

men

9 931

53,2

46,8

10415

53,0

47,0

2011/2012

22 227

11 956

10 271

53,8

46,2

2012/2013

22 279

11 882

10 397

53,3

46,7

Source: Ministry of Human and Minority Rights of Montenegro and Statistical Office of Montenegro (2014), Women and Men in Montenegro

During 2012, 2923 students have graduated at the undergraduate studies. Of the total number of graduated students at the undergraduate studies, 60.5% were female and 39.5% male students. During 2012, 282 students have completed the master studies, of which 63.5% were female and 36.5% male students. Gender inequality is also reflected in the segregation of educational profiles, where the traditional division into male and female professions still prevails. The female students are mostly enrolled at faculties of social sciences and faculties of art, while technical colleges are dominated by men. Traditionalism in relation to gender roles results in a higher technical illiteracy of women, which later additionally marginalizes them in the labor market. As regards the professions in Montenegro in civil engineering there are 23 high schools and 3 faculties for education of personnel in the field of civil engineering, who study for qualification of IV level of education:

technician for building construction, technician for civil engineering construction, technician for hydraulic engineering, technician of architecture and geodetic technician land surveyor. As regards the qualification of III level of education, in the Montenegrin formal education system there are no conditions for education of: tinsmiths, tilers, locksmiths, welders, operators of heavy machinery, installers, installers of sanitary appliances and air conditioners, hydro-civil engineer, electrician, installer of dry material. In the system of higher education, there are five faculties in Montenegro for education of personnel for construction purposes, such as: Faculty of Civil Engineering, Faculty of Architecture, Geodesy, Faculty of Electrical Engineering and Faculty of Mechanical Engineering. When analyzing enrollment by gender at the Faculty of Civil Engineering of the University of Montenegro, we may note the growth of enrollment of students in recent years.

Table 4: Enrolled male/female students at the Faculty of Civil Engineering (undergraduate studies) School year 2012/2013

School year 2013/2014

School year 2014/2015

School year 2015/2016

Women:

Men:

104

121

109

Enrolled:

147

198

206

160

Undergraduate studies

Source: Student Administration Office of the Faculty of Civil Engineering

CONCLUSION The level of education of women in Montenegro has long been equated to the education of men. In the field of civil engineering the situation has been improved in recent years, although it is still dominated by men. Equal gender opportunities in employment should come as a result of such situation, given that education is defined as the most important factor of vertical mobility and as powerful instrument for prevention of social 152

exclusion. However, the data show that women fail to provide high quality employment and successful careers to the same extent as men. Certain industries and professions are still hardly accessible to women, although the situation in civil engineering has been changed to the better. Inherited inequality and the issue of women from the previous period are still being conveyed further.

Journal of Applied Engineering Science 14(2016)1, 366

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Women in Montenegro are faced with different barriers in vertical mobility, what resulted in their weaker professional aspirations and choosing of stereotyped occupations. The deficiency of women in leading positions, as well as in owing properties and business entities, shows their position in society. Education is one of the main factors that influence the key obstacles to achieving gender equality in Montenegro and overcoming the rooted stereotypes on the educational choices of women for acquiring appropriate, technologically advanced and economically promising qualifications. REFERENCES 1) H. Gudjons, Pedagogy: basic knowledge , Educa, Zagreb, 1993, p. 162 2) P. Gazivoda: Educational vibrations , Institute for Textbooks and Teaching Aids, Podgorica, 2006. p. 128 3) D. M. Savi!evi!: Comparative andragogy , Institute of Pedagogy and Andragogy, Faculty of Philosophy in Belgrade, Belgrade 2003, p. 23

Journal of Applied Engineering Science 14(2016)1, 366

4) B. K. Lazarevi!: With education to recreation , Adult Education Society, Belgrade 2007, p. 1 5) J. Delors...et al.: Learning: The Treasure Within , Report of the UNESCO International Commission on the Development of Education for the Twenty-first Century, Educa, Zagreb 1998, p. 269-281 6) J. Delors...et al.: Learning: The Treasure Within , Report of the UNESCO International Commission on the Development of Education for the Twenty-first Century, Educa, Zagreb 1998, p. 19 7) J. Delors...et al.: Learning: The Treasure Within , Report of the UNESCO International Commission on the Development of Education for the Twenty-first Century, Educa, Zagreb 1998, p. 13 8) J. Denison: Technology, higher education and economy a critical attitude . The ways of education foreign experiences, Sa a Nedeljkovi!, Belgrade 1991, p. 101-111 Paper sent to revision: 28.01.2016. Paper ready for publication: 03.03.2016.

153

Original Scientific Paper

doi:10.5937/jaes14-10217

Paper number: 14(2016)1, 367, 154 - 162

SPACE OF THE REGIONAL AGGLOMERATIONS AND RE-INDUSTRIALIZATION Mikhail Valerievich Shubenkov* Moscow Institute of Architecture, Associate Member (A.M.) of the Russian Academy of Architecture and Construction Sciences, Moscow, Russia Dmitriy Alksandrovich Khomyakov MIA, City planning department The article is devoted to the analysis of the potential to fabricate production processes and their accompanying infrastructure networks as a part of urban areas. The authors explore the mechanisms of expelling production and services to outskirts by modern post metropolises . The processes showing how industries return to big cities and overcome urban fabric, stating their areas as promising targets to outbound investments, have been analyzed for the first time. The survey findings have revealed the possible ways to increase self-sustainability of cities and reduce consumption of external resources as well as to increase their efficiency due to different factors including distributed energy generation and consumption systems. Key words: Industry, Area, Agglomeration, Network, Efficiency, Infrastructure, Personalization, Self-sustainability, Energy efficiency INTRODUCTION In the recent years there was an upheaval that changed understanding of the urbanism theory and the mechanisms of urban processes with their impact on the planet. «Nonurban» establishments play a significant part in these processes as well, and the city itself is perceived as specially differentiated unity with varied morphology and patterns of scales, and it is taken as a process rather than a final product. Meanwhile the notion of urban agglomeration is still a core issue in analytical researches, although it is perceived as a mere « one of the array of measurements and official aspects capitalist urbanization» [6, p. 16]. According to the Professor Neil Brenner at Harvard Graduate School, it is intensification and global expansion of the capitalist production system is a true reason for the modern «changed» urban state of an enormous amount of completely different areas being far beyond agglomerations, and being no longer outskirts. Over the last 100 years urban fabric expansion was primarily generated due to increase in housing development, so planning was focused on this very aspect. Housing demand was constantly encouraged by migration flows from rural settlements to cities induced by industrial boom and agricultural decline. And, it is no doubt, that

technological networks of city services and production processes altogether are key issues in fabricating the potential urban development. Evolution of the term and the phenomenon of agglomeration itself passed the Fordist stage with its massive manufacturing and the concept of the big center as a backbone. At the early metropolis development stage big cities were centers of gravity showing ultimate congestion of people, activities and functions. Today there is a term «post metropolis» [7, p. 14] it has a centrifugal effect driving out basic production of goods and services beyond city spaces. This phenomenon is called «ex-urbanization», and is characterized by development of housing, infrastructure and city landscape outside the city. Due to globalization, which caused alienation between management and production, goods consumption and industry restructuring, significance of space concentration, was not diminished, and, on the contrary, went beyond to the new level: now we bear in mind regional agglomerations, where centers and knots have their own facilities in service. Spatial configurations of agglomerations are no longer based on the ongoing physical shape of the city but on the flows of different types of activities, which form functional unity. As to the cities development on the international level, besides the general trend of increase in city population

*Moscow Institute of Architecture, Rozhdestvenka 11, 107031, Moscow, Russia; mikhail.shubenkov@mail.ru

154

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

and cities growth, nowadays the phenomenon of the cities losing population is generally accepted. Thus, there was a proof of the necessity to create a new upheaval in the theory of cities development switching from the growth towards understanding of changes as dialectics of growth and reformation, and decline as well. INDUSTRY AND SPACE OF THE MODERN CITY Recently, opposition of an old industrial model to creative and new economy of knowledge appeared to be an integral part of the movement towards progressive modification of reality, in spite of the fact, that just a few decades back manufacturing was the key of economy and basic leverage of modernization in many countries. Nowadays, on the contrary, it is generally accepted that there are risks and negative impacts of one-sided economic models with individual hypertrophied sectors, whether they were ser-

vices or finances. In the west, there is a trend of industries going back to towns in a new manner: new types of activities development, new technologies, including digital design, engineering design, testing and manufacturing, backed by internal professional services and innovative technologies. It is referred to a new industry requiring appropriate areas. It is highly important to consider in detail and evaluate which possibilities were open for regional economies by globalization, and whether the concept of noisy and polluting industry isolated from cities has passed away. . Industrial area Santa Margarida II with the area of 55 hectares in the city of Terrasa, Spain. Mixed-use «area» of manufacturing and commercial activities (incl. huge leisure center «Par Buyers») tending to be considered as completely integrated into the city structure. However, it may be perceived being far beyond an ideal one.

Figure 1: Industrial area Santa Margarida II

Since it has been clarified that competitive advantages of more flexible and geographically independent manufacturing processes (mainly in developed countries), as in case of the suburban resettlement model, may appear provided there are combinations of artificially created favorable factors. But as soon as the situation and environmental costs change, general economical Journal of Applied Engineering Science 14(2016)1, 367

uncertainty along with the growth of expenses for production go to the foreground (manpower, transit, taxes, changes in customers requirements, threats of natural disasters growing up to 3% annually over the last 30 years), the necessity for further transformation of this economy sector and its reactivation on the local level (i.e. its return to the country to reduce depressiveness 155

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

and fragmentary nature of actions) is getting more evident [8, p. 95]. Certainly, the situation will never come back to its previous state since international enterprises got the leading position long beforehand in different industries, and technological changes and frequent crises force various activities and employees constantly migrate between companies and industries supporting a high level of mobility. But, in an case, it is unlikely that there will be the need to chose between economy of knowledge and industrial production (manufacturing, processing) inside the country: according to the findings of the survey made in the USA there is simply no need to do that, because an excessive gap between the final stage of production and research and development innovations, eventually, starts to generate negative impact [10, p. 23]. As it is known the grounds for the ideology of the postindustrial society were new labour markets and reduction of costs related to transportation and communication, which weakened protective role of distances when it comes to dispersed expansion of enclaves. Thus leading positions were taken by outside areas with their extensiveness and low cost, taxes and salaries. But a consequent collapse of the real estate and finance markets in the end of the first decade of XXI century forced neo-industrialization to develop, that s why a lot of western countries call for support and investments « as into enterprises, and their ecosystems» [09]. There are true evidences in favor of the significance of the city agglomerations when it comes to the knowledge expansion [4], and there are also detailed reports that prove connection between industry and innovations [8, 10]. From the one hand, industries take an active part in the research and development and innovative works (English: R&D&I - Research, Development and Innovation) when it comes to both investments into innovations and their implementation, and from the other hand industries are the first consumers of innovations produced in the service sector. That s why existence of production in the city system does not counteract with the strategy of the cities and agglomerations contributing to be a part of the knowledge society . Today we deal with enterprise chains with various locations, cooperating with other numerous companies that imply a solid network enterprises and spatial fragmentary nature of industry [10, p. 156

78]. This non-integrity can be explained by varied favorable factors, which are sought after by each industry segment when choosing an appropriate location. And, it becomes more clear, why industries vanish from the cities moving to countryside industrial parks and areas (particularly, as to E. Glazer, it s typical for mature industries which passed their most innovative stages in the central cities willing to reduce costs by moving to outskirts [4, p. 32]), leaving their representative offices in the central cities to keep the image on the appropriate level.. Thus the scales of establishments tend to be reduced allowing the urban fabric to become more «fine-grained» and permeable, and all the rest segments of the enterprises tend to be regrouped. Consequently, both the city and the industrial enterprise can win, by reducing staffed increasing outsourcing of different professional services. Recognition of this relatively new urban hybrid economics is highly important to realize the significance of such a complex territorial unit as the metropolitan(regional agglomeration), which contains final amount of all the inter-related components and works in production and services sectors broadly expanded outside the city. Trends in the terms of spatial distribution can be described as follows: central location of the service sector assigned for urban manufacturing, outbound dissipation of the manufactures and formation of local industrial clusters outside the city. Foreign experience over the last fifty years highlights univocal dynamics of the industry move, which started at the stage of ultimate popularization in the big regional cities transforming into much more industrially balanced vast metropolitan regions, where industrial areas and logistics parks make up a network (quite often) on the basis of small-sized and medium-sized cities and efficient highway infrastructure joining them to the capital [10, p. 145]. There is a possibility to boost the growth due to availability of free area, but there is also a concern about well-known trends of the free market, where it is always reasonable to minimize costs for lands, which inevitably drives out industry as far as it is possible from the city centers without due account for consequent difficulties related to service delivery and employees (this is a common issue when it comes to land development and functional activities layout when converting of land plots into objects for residential and inJournal of Applied Engineering Science 14(2016)1, 367

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

dustrial use turns out to be highly profitable business, but not key strategic points in development of region). Figure 2 present Multi-functional distribution and exhibition center BMW Welt in

Munich, Germany. It is located very close to the head-quarters of the company, Olympic park, industrial area and residential districts with underground (subway) lines.

Figure 2: Multi-functional distribution and exhibition center BMW Welt

In the EU countries (France, Spain, Germany, the Netherlands) and in the USA, over the recent years, relations between the city and industries were subject to be systematically reconsidered in favor of protection and reanimation of the manufactures since the long-term externalization of manufacturing processes was declared as dangerous for ability of any state to introduce innovations and compete. It is planned to build new relations on the basis of the combination of strong points related to area proximity, labour market availability, complex nature and ecological performance. Extreme specialization, standardization and functional segregation of the Â&#x2018;FordistÂ&#x2019; model associated with the massive production, which expelled industries outside the city and caused an appropriate area planning, are now exceptionally criticized. Scattering of manufacturing agglomerations over the regional areas based only on low land cost, which followed right after the mentioned above stage, is claimed for emergence of a big range of industrial areas with infrastructure of low quality. And it should be noted that the growth of urban arJournal of Applied Engineering Science 14(2016)1, 367

eas of low quality, whether they are industrial or residential ones, as a result, faces the problem of degradation, premature deterioration and environment depreciation, where there is less encouragement and possibility to regenerate, and, quite often, there is no way to influence on the areas and adjust them to new requirements. So there is an issue of technical, economical, moral, social and special deterioration, and it is not only about depreciation of environment due to its long-term use. In summary, foreign researchers [10, p. 182] claim that it is a mistake to make industrial areas isolated from the city life due to spatial barriers and push for considering new industrial areas as a mix-use eco-complex and an integral part of the city environment, which they should be close to, or intensively contact with each other. RUSSIA: REGIONAL AREAS AND MANUFACTURING INFRASTRUCTURE In Russia, with the problem of non-uniformly distributed developed regions, the trend of Â&#x2018;de157

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

velopmentalism (development as growth and modernization) may be considered as reasonable and appropriate, at least, if it is going to be focused on as urban areas growth as rearrangement of already utilized lands and manufacturing resources allocation taking into account settlements and environment. In this regard it is highly important to consider these land plots firstly as infrastructural grounds for industrial and social and economical progress, and not as an end itself and profitable business. In real life, being focused on the infrastructure development in regions, it appears to be an efficient tool to attract outbound investments into local sector

of economy and to expand local small and midsized manufacturing businesses (which are primarily interested in ready-to-use property lease, possibility to develop industrial parks completely equipped with engineering and transportation communications). According to analytical reports investors are looking forward to going to the western and central parts of Russia in 2015 (and cross-border regions near the countries-members of the Shanghai Cooperation Organization), and the major criterion to choose the location is proximity to the Russian and Euro-Asian crossborders (besides clear legislative and executive framework and taxes costs reduction) [02].

Figure 3: a) Industrial congestion, b) industrial parks in Moscow region

The Figure 3, a) shows from top to right: map showing the shares of regions in industries, from 16.5% (red colour) up to less than 1% (light-yellow). In the center: congestion of industries and electric power stations in the region (source: Kolosova, N. N. Atlas Moskovskoj oblasti uchebnyj (serija «Sfery»). M.: Prosveshhenie, 2004). The Figure 3, b) shows Map of industrial parks in Moscow region valid for 2014. Land plots are classified as ready-to-use ones, under development or under planning, and the potential of the regional districts (classification is based on the industrial potential, human resources, tax environment, investments and transportation infrastructure) as high (orange), medium, low and insignificant (dark-red). It is the copyright of the British audit company «Ernst & Young» (E&Y) If we take congestion of infrastructural investments in Russia it will be possible to identify the 158

leaders by the amount of linear infrastructural projects under development and under planning (infrastructural projects are generally accepted as highways, bridges, air and railway and water transportation, energy and water supply facilities). And they are mainly the Ural, Pryvolzhsky and partly Northwest, Southern and Far Federal Districts [3]. But nowadays, when it comes to infrastructures required to run businesses, there can be enlisted such more complex non-linear establishments as industrial parks (i.e. industrial and logistics areas), export-processing zones, business incubators, innovative clusters and etc. At the moment the majority of industrial parks are congested in the European part of Russia (totally by the beginning of there are 366 industrial parks in Russia): 37% - in the Central part of Russia and 17% in the Northwest and Pryvolzhsky Federal Districts each. [3, p. 10]. Most of the private Journal of Applied Engineering Science 14(2016)1, 367

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

industrial parks are in Moscow region, and the major part of them is represented by non-developed lands amounting to 500-900 ha, which in most cases adjoin to existing low-rise residential settlements. But soon the landscape of radial mains the region will change completely: the area between mains will appear to be industrial corridors , which will create solid urban environment with no gaps made up of scattered settlements. And there are certain industrial parks planning to apply new ways of zoning allocating areas to be used for social and business purpose (with housing and social infrastructure) and for commercial purpose (offices, manufacturing and warehousing, e.g. an industrial park Koledino in the Podol sky region) with due account for recreation and public zones being a buffer between industrial parks and existing settlements. Other development projects do not replicate such integration methods. As to the worst scenario we may expect that there will be a complete deterioration of the suburban value system in these areas due to invasion of the large impermeable industrial areas causing repeated refuge of dwellers to remote regions. As to the best scenario there will be an opportunity to consolidate regional centers on the basis of small and midsized cities (Klimovsk, Kolomna, Volokolamsk, Klin, Dmitrov and others), which will contribute to decentralization of employment in the region. But there is an issue that should be expected in any case, and it is growth of areas with high population density in the region: in the presentations of industrial parks, which claim to have complex mid-rise housing development, in fact, we may primarily see high-rise housing (see: http://m2-podolsk.ru/presentation/koledino. pdf). New large retail-parks and mega malls will complete the panoramic view But it is in the theory. We may state that the share of ready-touse industrial parks significantly increased (from 29% in 2010 up to 44% in 2015 [3, p. 12]). Now we may observe that there is a drop in settling of these industrial parks, and construction of already designed large shopping centers (75-450 thousand sq.m.), will be probably postponed for long time or even cancelled (this was the forecast made by analysts at the Roundtable Board «Kiosk VS shopping mall: how shopping patterns may impact on the city environment» during the Moscow urban festival in the end of October 2015). Journal of Applied Engineering Science 14(2016)1, 367

EFFICIENT CITY DISTRICTS The concept of completely personalized industry in the framework of so-called third industrial revolution causes controversial estimates. Some people mean total self-sustainability of a person who produces all the material values and goods at a home workshop (3D printing e.g.) or at a private backyard such a chimera a regressive and extreme mixture of ecologism and technocracy implying the end of the centralized industry, employment and trade (nevertheless scientific centers, which promote interaction between information technologies and environment, have been existing over fifteen years, and manufacturing workshops «Fab Labs» able to become the core of the new patterns for microenterprises have been operating in more than 20 countries [5, p. 117]). Others claim that information transfer methods and manufactures are inevitably to be digitalized: they are fascinated with the challenge to radically exchange the concept of taking unnecessary parts of natural resources away to obtain final products, which leads to waste emergence, with the concept of supplementing only required materials in favor of massive personalization of the product with its ultimate geometrical complexity. In this case location of such a manufacture is no longer an important criterion, which makes it possible to reach final customers and rapidly meet changes in demand. There is also no need to transfer searching for cheap labour It should be noted that there is a possibility to spread new hybrid types of industrial spaces close to housing in the city: areas and buildings joining people in groups by the type of the equipment and by working patterns, and not by membership of an enterprise. In any case the concept to consolidate the model, which overcomes centralized industrial sstems in favor of new network structures, is to be considered. Distributed production systems on the basis of interrelated self-sustained units may be evaluated as flexible and able to adjust to changes. And we also have not yet mentioned exposure of current city systems to serious risks under possible collapse of the centralized model of energy supply and oil market shocks. Such risks as a damage of long-spanned infrastructures (railways, electric power lines) due to frequent natural disasters should be also mentioned. Regardless of the discourse to return industrial areas into the cities there is an issue 159

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

of ceasing to be just dwelling settlements, which only consume resources and become efficient particularly but not exclusively due to urban fabric itself. In this case, efficiency is a broad term and means possibility to add value to city areas (besides converting areas from environmental to urban ones) due to modernization of planning and design. This implies introduction of the following components: small-scale technologies to generate energy (hybrid systems in each house or neighborhood); economical mode of joint use of resources and objects; distributed manufacturing models; intensifying development of agglomerations); change of a prevailing type of property management in favour of renting; innovative corporate models of investments and management of city infrastructures; protection of linear infrastructure under climate changes and extreme weather conditions in the nearest future and etc. [05]. What is crucially important for coordinated city activities inside regional agglomerations is that there is a possibility to develop these cities as direct and responsible boosters for manufactures

and technological innovations ceasing to be just consumers. Thus provided these so-called metropolitan areas» agree about relatively general requirements and needs of the city systems (any type of the progressive city standards, e.g. transportation, infrastructure and public areas), then it will be easier for them, being major customers, to resort to manufactures to satisfy these needs due to large-scale orders for innovative goods and materials (a classic example cooperation of the Brazil city Curitiba and the group of companies Volvo). This is one of the aspects of the hidden city potential able to create own economy on the basis of transformation of its functioning (i.e. management and supply of high-tech smart city services as an economic activity [5, p. 189]), and not only because of urban fabric reproduction and extending while construction. Generally speaking, management (e.g., energy supply and etc.) and long-life service of areas (housing or infrastructure) executed by property management companies city economic activity which may become basic in the nearest future.

Figure 4: Industrial perk «Koledino» (340 ) in the Podol sky district in the Moscow region (the nearest large settlement Klimovsk).

Figure 4. Industrial perk «Koledino» (340 !") in the Podol sky district in the Moscow region (the nearest large settlement Klimovsk). Figure 4, a): Status of the areas adjoining to the city of Klimovsk (borders marked with red colour) from the Northeast dated back to 2005 (source: Google map, 2005). Figure 4, b): Process of filling the area between mains with new urban land plots low-density housing, manufacturing and warehousing. Status in 2015 new areas are marked with yellow colour, incl. Koledino, around which an industrial park is planned to be developed (source: Google map, 2015). 160

Figure 4, c): Functional planning and zoning of the industrial park «Koledino» (it consolidates fragmented urban areas of the Klimovsk district) including as follows: manufacturing and warehousing of the hazard class 5 (1); public infrastructure (2); public and business area (3); residential development (4); recreation zone (5) and retail park (6). Whether the location of industrial areas is favorable or not it comes from real life aspects to be improved: soundness to keep its industrial status and necessity for reorganization (in particular, it is the case of industrial areas within the city), which are generally and officially Journal of Applied Engineering Science 14(2016)1, 367

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

accepted both in Russia and abroad nowadays [1]. Against all the odds, it is still top-of-the-agenda to keep strategic grouping of enterprises following the principle of complementarity in the course of production chain (agglomeration of basic and supplementary manufactures), which makes it possible to reduce time and delivery costs. As we may see there are no grounds to expect eventual fragmentation and crushing of area sizes, though the goal to achieve the permeability and ability to integrate such large land plots into urban fabric is still up-to-date. There are still good arguments of getting more active in favour of the existing industrial areas, which are in a desperate state. Enterprises quite often leave serious ecological problems (accumulated wastes) to be disposed of, and disintoxication of the areas may make housing and office projects much more expensive. There are still specialists in the cities with dying-away manufactures, and it would be reasonable to rely on them. It is also important that city-forming enterprises remained infrastructure and electric power stations, though the need to be advanced. Manufacturing, as well as housing development, can t be separated from the process of expansion and spreading of the infrastructural networks. But these networks are not only inert technical systems, they have higher value: they represent the basis of the modern way of life and are involved into cultural and political process of the society, and their availability of lack may cause emergence of areas of social inclusion, as well as areas of segregation. Manufactures should be considered as places of energy consumption, and as an organizing special element to be responsible for the amount of energy consumed for transportation since its location is related to allocation of service outlets and houses and etc. Thus it is recommended to focus on interaction between different systems (displacement of population, industries, manufactures) and energy consumption, infrastructure and social city models. CONCLUSION A real life and up-to-date space of a resident, where he or she lives, works and has a rest, goes far beyond traditional boundaries of his or her flat, house, district and city. Today he or she moves within fractional areas of the network made up from urban cores, natural zones and Journal of Applied Engineering Science 14(2016)1, 367

infrastructural networks which join them all together. Sizes of such a noncontiguous metapolis are defined by implementation of regular human activities, which have impact on the areas leaving after-effects. In the same way, as in the case of preferred transportation types, it is reasonable to develop a synthetic model in the city planning instead of making stake on certain models. This model combines advantages of living in small settlements with the best patterns of city density and responsiveness. This concept, described in numerous surveys, is accurately summarized by Vicente Guallart as «a variety slow cities as a part of a «smart city» » [3, p. 31]. This expression is backed by the following statements: !) we implement processes of daily-life activities simultaneously at different levels with different special scales (flat, house, district, city and region and etc.) and b) special level, at which people can satisfy their needs, may be defined by a certain type of a city: in the cities, where shops and small-sized manufactures are closely located, people may walk; in the cities, where shopping malls and large-sized manufactures are remotely located, the demand for a car is increasing, i.e. already today different models of mobility, density and human relations. Coexistence of different velocities inside the city is possible: mobility with low velocity is suitable for regions and districts with hybrid functions, and mobility with high velocity is suitable for ecological city, intercity, international public transportation in largescale structured agglomerations. The concept of the smart city implies preliminary reengineering process (works related to supplementary engineering and technical equipping of the city), which makes it possible to interchange information and immediately reprogram city processes and services. Different models of production and consumption imply land and city planning, living standards, and arrangement of economic and environmental impacts to different extents. And if there is a need to make a vertical leap from one level to another one (i.e. from macro- level to micro- level for a certain consumer) to connect functional knots (e.g. power production) with the final customer of the material values, then it will be necessary to develop a supplementary large-scale network (infrastructure) to connect all these various levels. This fact should be acknowledged and always taken into account. And that s why the idea 161

Mikhail Valerievich Shubenkov-Space of the regional agglomerations and reindustrialization

of self-sustained buildings, districts, regions and cities, arranged in a horizontal network (where, first and foremost, generated power, information and knowledge are distributed and transferred), has arisen. The network is monitored so that if one part is shut down, then another one continues to operate. In order to implement this it is inevitably required to provide buildings with such distributed intelligent systems (e.g. power production and monitoring), which are to be integrated into structures, and turn them into producers, because they only and entirely consume resources nowadays. REFERENCES 1) Egorova, E. (2015): Rezidenty vstretjatsja v tehnoparke, Moskovskaja perspektiva, ! 33, 5 p. 2) Mark, N. (2015): Regiony zazyvajut investorov v parki, zony i TORy, TPP-Inform: Torgovo-promyshlennye vedomosti, Vol 4, 9 p. 3) R. Dobbs, G. Strube (2015): Proizvodstvennaja i innovacionnaja infrastruktura Rossii. Demonstracionnaja versija obzora / Ernst & Young Global Limited (EY). 49 p. 4) Glaeser, E. L. (2009): The wealth of cities: agglomeration economies and spatial equilibrium in the United States, Journal of Economic Literature. ! 47(4). pp. 983-1028.

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5) Guallart, V. (2012): La ciudad autosuficiente: habitar en la sociedad de la información, Serie: Política y Sociedad, Barcelona: RBA Libros, 236 c. 6) N. Brenner (2013): Implosions/explosions: towards a study of planetary urbanization, Berlin: Jovis, 576 p. 7) R. Caracciolo, P. Elinbaum, B. Horrach, M. Debat (2013): La metrópolis iberoamericana en sus propios términos: opciones al crecimiento infinito y a la crisis institucional, Barcelona: BCN Digital SA, 205 p. 8) J. Manyika, J. Sinclair, R. Dobbs, G. Strube (2012): Manufacturing the future: The next era of global growth and innovation, McKinsey Global Institute. London, 170 p. 9) C. Gewerc (2013): Opinion of the Committee of the Regions on «A stronger European industry for growth and economic recovery, Official Journal of the European Union, Vol. 56. pp. 11-16. 10) M. Buhigas (2014): Torna la indústria. Estan preparades les ciutats? Gabinet de Premsa i Comunicació de la Diputació de Barcelona. Cornellá de Llobregat: Nova Era Publications, 295 p. Paper sent to revision: 04.02.2016. Paper ready for publication: 01.03.2016.

Journal of Applied Engineering Science 14(2016)1, 367

Original Scientific Paper

doi:10.5937/jaes14-10472

Paper number: 14(2016)1, 368, 163-168

EXPERIMENTAL TESTING OF COMPOSITE SANDWICH PANELS WITH DIFFERENT FACE SHEETS Ana Trombeva-Gavriloska* Faculty of Architecture, Ss. Cyril and Methodius University in Skopje, Republic of Macedonia Marijana Lazarevska Faculty of Civil Engineering, Ss. Cyril and Methodius University in Skopje, Republic of Macedonia Meri Cvetkovska Faculty of Civil Engineering, Ss. Cyril and Methodius University in Skopje, Republic of Macedonia An experimental tests performed on two series of sandwich panels, differed by the type of the matrix used for the composite face sheets, are presented in this paper. By applying a linear load in the middle of the span, these sandwich panels were subjected on three points bending test. The analysis was performed in order to evaluate the influence of the matrix type on the ultimate mechanical characteristics of the sandwich panels. By analyzing the F-! behavior of the sandwich panels, as well as the F-" behavior of the composite face sheets, the influence of the matrix type used in the composite face sheets has been evaluated. Key words: Composite sandwich panels, Mechanical properties, Experimental testing INTRODUCTION Sandwich elements are being often used as constructive elements in civil engineering structures. The usage is mostly based on their high performance, such as high stiffness and high strength, in comparison with their weight. Based on the concept of increasing the bending bearing capacity and stiffness, sandwich panels are defined as structures that have low weight. They are multi layered composites formed of two thick, but strong and stiff face sheets, and weak core. Depending on the specific application of the final product, different materials could be used for fabrication of sandwich panels. Any constructive product available as a thin plate could be used for the face sheets [02]. Materials are chosen so that face sheets will have high bending stiffness, high tensile and compressive strength and excellent resistance to external influences. Composite materials, as anisotropic materials, especially as materials with high strength to weight ratio, high stiffness to weight ratio and as non-corrosiveness easy handling material that offer many options in the design process, are very often used as materials for the face sheets.

Lingaiah and Suryanarayana [05] in their work present experimental research of sandwich panels with composite face sheets and aluminum honeycomb core subjected on bending, while the Alias [1] did experiments on sandwich panel with steel face sheets and polyvinylchloride core statically loaded with concentrated force. The fracture mechanism should be well-known in order to determine the mechanical characteristics of sandwich panels. Fracture types of sandwich panels in linear part of the behavior, are studied and discussed by Allen [02], Ashby and Gibson [03] and Plantema [08]. In order to simplify the mathematical operations numerous analyses of sandwich panels are being performed on beam models. Swanson and Kim [9] and Mines and Alias [07], were focused on analyses of sandwich beam fracture. Fracture of the sandwich elements could occur as a result of reaching the ultimate compressive or tensile strength of the face sheets or as a result of reaching the ultimate shear strength of the core [6, 4]. According to the available literature the mechanical characteristics and the fracture type of the sandwich panels depend on the materials used for construction. Mechanical characteristics of sandwich panels

*Faculty of Architecture, Ss. Cyril and Methodius University in Skopje, Goce Delcev 9, 1000 Skopje; agavriloska@arh.ukim.edu.mk

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with composite face sheets depend also on the components used for the composite material. This paper presents an experimental tests performed on two series of sandwich panels with composite face sheets, differed by the type of the matrix used for the face sheets. Two types of matrix materials, polyester and epoxy based resins, are used for this experiment. Sandwich panels were subjected on three points bending test. The analysis was performed in order to evaluate the influence of the matrix type on the ultimate mechanical characteristics of the sandwich panels. Influence of the matrix type used in the composite face sheets was evaluated by analysis of F-! behavior of the series of sandwich panels, as well as by analysis of F-" behavior of the composite face sheets.

PROPERTIES OF SANDWICH PANELS AND TEST SET UP COMPONENTS OF SANDWICH PANELS For the purpose of the experimental testing two different series of sandwich panels have been fabricated. The examined sandwich panels were fabricated of polyurethane core and thin composite face sheets. The core of sandwich panels was 60 mm hard foam polyurethane with density of 30 kg/m3. Actually, the sandwich panelsÂ&#x2019; series differ by the type of matrix used for the thin composite face sheets. The thin composite face sheets were fabricated using two types of matrix and fiber glass reinforcement, rowing with density 0,535 kg/m2, in two plies. The materials used for production of the sandwich panels are summarized in Table 1.

Table 1: Components of series of tested sandwich panels Sandwich panels

Core

SP2R SE2R

Face sheet Matrix

Reinforcement plies

Reinforcement

Polyurethane

Polyester resin

Rowing

Polyurethane

Epoxy resin

Rowing

The sandwich panels were marked in accordance to the components used for the production of composites face sheets: the first symbol refers to the sandwich panel (S), the second symbol refers to the type of the matrix (P or E), the third symbol refers to the number of reinforcement plies (2) and the last fourth symbol (R) denotes the type of the applied reinforcement. SPECIMEN GEOMETRY

polyurethane. Their geometry was defined by the properties of the test machine, Figure 1. All test specimens had a constant length of 1000 mm and rectangular cross section with width of 300 mm. The depth of each sandwich panel differs depending on the depth of the composite face sheets. For precise determination of the relative strain of each composite face sheet of the tested sandwich panel, strain gages in longitudinal direction were used.

Test specimens were fabricated by hand lay-up of the composite face sheets on the hard foam

Figure 1: Geometry of sandwich panel specimens 1) composite face sheets; 2) core; 3) strain gages

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Journal of Applied Engineering Science 14(2016)1, 368

Ana Trombeva-Gavriloska - Experimental testing of composite sandwich panels with different face sheets

EXPERIMENT TEST SETUP The final surface preparation was carefully examined for each test specimen prior to the flexural tests. The dimensions of the specimens were measured before the flexural test. In order to record the average area of the specimens, their area was measured at three places. Experiments were performed by the testing machine SCHENCK HYDROPLUS-PSB, with capacity of 250 kN. Tests were made in range up to 25 kN. The tests specimens were subjected on three point bending test. Additional device was set on the test machine in order to test the flat beams loaded on flexure. The specimens were carried by steel supports with 50 mm width set on 50 mm diameter steel cylinders which permit slip and deformation of the sandwich panels during the experiments. Slip on the contact surface was avoided by using of 2 mm neoprene layers between sandwich panels and the steel support. Line load was applied through 100 mm width steel beam mounted on steel cylinder with diameter of 50 mm. A 40 mm square hole was made in the middle of the steel beam in order to set a strain gage on the top face sheet of the sandwich panel in the middle of the span. By plac-

ing a 4 mm thick neoprene layer between steel beam and sandwich panel the local fracture of the top layers of the composite face sheet was avoided. The actual span of the sandwich beam was 800 mm and the load was applied with constant speed of 5 mm/min. Flexural force was determined with force transducer integrated in the testing machine. The full bridge strain gage type force transducer was used. Head displacement of the testing machine was determined by displacement transducer of inductive type. Strain data were determinate using strain gage in longitudinal direction. The strain gage with resistant of 350, type HBM 10/350LY11 were selected in order to reduce the heating effects due to the low conductivity of the used composite materials. The surface preparation and the selection of bonding agent for the strain gage installation was done in consultation with the strain gage producer. The temperature compensation was done by a passive strain gage, connected in half-bridge. The force versus head displacement and the force versus strain were continuously recorded with sampling rate of 50 Hz. The HBM Spider 8 and software HBM CATMAN 4.0 were used for data acquisition.

Figure 2: Testing machine and equipment for flexural test of sandwich specimens: 1) testing machine; 2) additional device for testing flat beams; 3) acquisition unit; 4) computer; 5) steel support lay on cylinder; 6) loading steel beam on cylinder

EXPERIMENTALLY OBTAINED RESULTS AND DISCUSSION The flexural testing has been performed on two different series of specimens. Two specimens of each serial were tested for the purpose of the ex-

Journal of Applied Engineering Science 14(2016)1, 368

periment. The geometry and the experimentally obtained results for tested sandwich specimens are summarized in the Table 2.

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Ana Trombeva-Gavriloska - Experimental testing of composite sandwich panels with different face sheets

Table 2: Geometrical and mechanical properties of tested sandwich specimens Face sheet thickness, t

Sandwich panel thickness, h

[mm]

SP2R_1

1,5

SP2R_2

Tensile strength

Load

Deflection

[N]

[mm]

3340

30,67

34,65

1,7

3367

29,08

29,18

SE2R_1

1,3

3538

32,27

41,48

SE2R_2

1,2

3511

32,58

45,07

Sandwich specimen

From the performed tests can be concluded that the behavior of the tested sandwich panels subjected on three points bending test can be divided in three characteristic parts. Behavior of the sandwich panels is linear up to the point where cracking of the polyurethane foam occurs reducing their stiffness. In the nonlinear part, by in-

[MPa]

creasing the load, new micro cracks appear and spread through the depth of the core, while the composite face sheets are still in elastic part caring out the applied load. In the last stage crash of the top composite face sheet and core occur followed by a considerable drop in the stiffness of the sandwich panels.

Figure 3. F-! diagrams for specimens SP2R and SE2R subjected on three point bending test

The F-! behavior of the tested sandwich panels SP2R and S"2R in the middle of the span is similar, as can be concluded from the Figure 3. The ultimate strength of the series sandwich panels SE2R is minimally higher in comparison to the series of sandwich panels SP2R. In particular, the behavior of the both series of sandwich panels is in the linear part with the approximately equal stiffness and minor differences observed in the ultimate deformations. In order to observe the influence of the used matrix on the mechanical properties of the sandwich panels, comparative analyses of the experimentally obtained results for the stress on the bottom face sheet were carried out, Figure 4. The analy-

166

sis of the results summarized in Table 2 lead to conclusion that the deflections and ultimate tensile strength in the bottom face sheets in each series of sandwich panels are approximately equal when subjected to ultimate load. I case of equal load, the series of sandwich panels SE2R have minimal higher stress in the bottom face sheet in comparison to series sandwich panels SP2R, as can be seen in Figure 4. Nevertheless, it should be mentioned that the stresses in the composite face sheets are very small in comparison with the strength of the composite material, and the properties of the composite material are not completely used.

Journal of Applied Engineering Science 14(2016)1, 368

Ana Trombeva-Gavriloska - Experimental testing of composite sandwich panels with different face sheets

Figure 4: F- diagrams for specimens SP2R and SE2R subjected on three point bending test

The results of the performed experiments state that the fracture of the sandwich panels was followed by fracture of the top composite face sheet and fracture of the polyurethane foam core

in the top of the sandwich panels, while the bottom composite face sheets remained undamaged with no visible cracks, Figure 5.

Figure 5: Fracture of the sandwich panels SP2R and SE2R subjected on three points bending test

CONCLUSION This paper presents results from the experimental tests of two series of sandwich panels subjected on three points bending test. Analyzing the experimentally obtained results it can be concluded that the type of matrix used in the composite face sheets doesnÂ&#x2019;t have a great influence on the initial strength of the sandwich panels and on their deformation. Similarly, the type of the matrix used in the composite face sheets doesnÂ&#x2019;t have an influence on the stress Journal of Applied Engineering Science 14(2016)1, 368

in the bottom face sheet, on the stiffness of the sandwich panel and on their ultimate bearing capacity. Experiments show that the fracture of the sandwich panels is driven by the characteristics of the polyurethane foam core. ItÂ&#x2019;s low strength and deformation characteristics have great influence on the fracture of the sandwich panels. It does not permit a utilization of the characteristics of the composite materials used for the face sheets.

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REFERENCES 1) A. Alias, N.A.A. Nor, M.R. Said: The Behaviour of Square Sandwich Panel. Part I: Under Static Loading , Journal Teknologi, 47, 2007, 1-18 2) H.G. Allen: Analysis and Design of Structural Sandwich Panels , Pergamon Press, Oxford, 1969 3) M.F. Ashby, L.J. Gibson: Cellular SolidsStructure and Properties , Pergamon Press, Oxford, 1997. 4) Q.M. Li, R.A.W. Mines, R.S. Birch: The Crush Behaviour of Rochacell-51 WF Structural Foam , International Journal of Solids and Structures, 37, 2000, 6321-6341 5) K. Lingaiah, B.G. Suryanarayana: Strength and Stiffness of Sandwich Beams in Bending , Experimental Mechanics, 31, 1991, 1-7

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6) R.A.W. Mines, A. Alias, Q.M. Li, R.S. Birch, J.A. Close: On the Measurement of the Crush Behaviour of Structural Foams , 11th International Conference on Experimental Mechanics, 1998, 287-292 7) R.A.W. Mines, A. Alias: Numerical Simulation of The Progressive Collapse of Polymer Composite Sandwich Beam under Static Loading , Composites: Part A, 33, 2002, 1126 8) F. Plantema: Sandwich Construction, The bending and buckling of Sandwich Beams, Plates and Shells , John Wiley & Sons inc., New York, 1966 9) S.R. Swanson, J. Kim: Design of Sandwich Structure under Contact loading , Composite Structures, 59, 2003, 403-413 Paper sent to revision: 26.01.2016. Paper ready for publication: 15.03.2016.

Journal of Applied Engineering Science 14(2016)1, 368

Original Scientific Paper

Paper number: 14(2016)1, 369, 169-178

doi:10.5937/jaes14-10064

STANDARDS AND COMPETENCIES OF THE EU - THE MARKET STRATEGIES OF FINANCIAL SERVICES IN THE BALKAN REGION Nada Vignjevi!-"or#evi!* State University of Novi Pazar, Novi Pazar, Serbia emsudin Plojovi! International University of Sarajevo, Sarajevo, Bosnia and Hercegovina New members joining the European Union, happily coincided with the economic rise worldwide. The investment industry has positioned itself at the time of European expansion in the emerging markets. Extended European capital market, preceded by a long period of preparation of the new members, in which they felt the positive effects of connecting with more mature markets. Experts point out that the World Bank policymakers eight new members of the European Union should adopt a proactive stance in taking further financial reforms and that in addition to the rapid growth of the banking system and stimulate growth in the form of non-banking financial operations. Increasingly important shareholders associated with the strengthening power of institutional investors. So stockholding strengthened with the help of representatives of institutions in the field of insurance, pension funds and investment funds. The subject of research are the impacts of changes in the insurance market taking into account the connection with the banking sector through a unique offer. The goal is to show greater dependence of the banking sector and insurance in the ever-growing competition with an innovative range of products. All the major part of savings managed by institutional investors. Savings realized the benefits of financial innovation, which have significantly lowered the cost of the invested money management services and improve the quality and diversity of investments. This gathering individual savings, have improved the efficiency frontier relations income-risk and on the other hand, over-sized achieve the economies of scale transactions. Also, depositors can expect a higher level of revenues for the same level of risk. Key words: Market strategies, Financial services, Standards, Competencies, EU INTRODUCTION The general objective of the regional approach, which is defined by the European Commission [17, p.123-141], in addition to the consolidation of peace and stability in Southeast Europe and to encourage and assist its economic regeneration. Basic elements of this process, the European Commission has defined as: Development Agreement as the basis of new types of contractual EU s relations with individual countries of the Balkans; Developing and improving existing economic and trade relations; Developing existing financial assistance, particularly through new financial instruments (CARDS); The development of political and business dialogue, including regional level.

The strategy of economic reform and regional cooperation, which represents, in fact, asymmetric trade liberalization, and on that basis contributes to the changing position of the insurance company only one side has improved conditions for preferential imports from the Western Balkan countries by granting emergency trade measures. Rules has expanded the scope of application of additional preferential measures, are duty-free treatment on 95% of goods originated from countries that are involved in the association. The most important institutional sectors in the formation and use of the reservoir at the level of macro system, hence the component parts of commercial sources and placements are: 1. Economy 2. Education, 3. Population, 4. Bodies and Institutions, 5. Banks and other financial organizations and 6. Foreign Countries. Seen from

*State University of Novi Pazar, Vuka Karad i!a bb, 36300 Novi Pazar, Serbia; midass@orion.rs

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Nada Vignjevi - or evi - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

a development point of view the most important economic sector positions in the formation of market and insurance resources and the use of credit. Complementary importance of a sector of the population. These as well as changes in the environment and within the companies themselves potencial all the complexity of managing changes in marketing management. As managers of insurance will increase more systemic, rather than strictly commercial and insurance oriented. This means that managers will be more in insurance strategists than previous operators, in order to achieve the evolutionary position of insurance companies in the market conditions. It will be in the full sense of the present innovative, almost revolutionary trends characteristic of the overall business environment. In the future we can expect a more rapid consolidation within the banking system [8, 52-68] and insurance, and increased competition, and from it will emerge more favorable conditions and a greater range of products that banks will offer. Reconfiguration, download, connection pooling and insurance companies through capital competition faced with various forms of non-capital development and growth of enterprises. The globalization of business activity [15, p.49-61] favors the establishment of various joint venture investments and strategic alliances in order to take advantage of opportunities in the regional market. NATIONAL LEGISLATIVE HARMONIZATION WITH EU REQUIREMENTS Harmonization of legislation of Member States [1, p.31-38] relating to the integration of the domestic economy in the EU common market [5,6,10], can be made positive and negative approach that is also described as positive and negative harmonization. Realization of positive integration consists in making of EU rules [9, p.1721] in a uniform manner applicable in all Member States. At the level of the common state, these properties have regulations / ordinances. As the regulations recognized the immediate application of the direct effect, and their uniform application achieves not only alignment, but also full alignment. Hence, in the theoretical sense rules are not a means of harmonizing the rights of member states, but a means to equalize the application is not transformed into harmonized national 170

legislation, but remain as a single supranational regulations. Economic developments after the creation of the EU is characterized by two processes that occur simultaneously: - - Harmonization of the national legislation of EU member states, and - - Creation of specific subjects of business. Responsibility of agencies and organizations in the public sector is much rigorous than the responsibility that is required in the private sector. For this, there are a number of reasons, most of which are based on the fact that proper and timely payment of taxes and other public revenues in the public interest, not the interests of individuals. On the other hand, services that service the ministries and other state organs intended for the population as a whole, not individuals. The users of these services can not go somewhere else and buy such a same service, if it considers that it is not getting the right value for your money, so it is necessary to establish mechanisms of accountability of public service providers which will ensure the proper regulation of the use of public funds. Capital construction programs and plans investments are very important in every country, especially in countries in transition [21, p.97-112]. Nature and scope of investment for individual development projects assumed security in general require funding from real sources, such as budgets, loans from the country and abroad, grants and other funding sources. Determined and approved investment programs [22, p.264280] are implemented by signing a series of contracts between the state or state agencies or other organizations designated by the State, with a corresponding credit institutions and banks in the country and abroad, and from the state, public funds or organizations that are designated by the state (for example, the Development Fund, and the like) and the providers of the programs, service providers and other suppliers of material goods. Then, there are agreements between the State and the representatives appointed government bodies and regulatory authorities, on behalf of investors who oversee and control the execution of contracted projects and a number of other contracts for various brokerage and other services. As a rule, the development plans and programs are long and divided into shorter intervals, to facilitate their effective monitoring, registration, analysis and verification. In the imJournal of Applied Engineering Science 14(2016)1, 369

Nada Vignjevi!-"or#evi! - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

plementation of Â&#x201C;stateÂ&#x201D; or investment contracts, or contracts which are related to the realization of investment plans occur in practice setbacks due to inefficiency, then exceeding the approved

funds, financial loss, fraud, theft or damage to inadequately secured equipment, works and various other financial fraud, corruption and the like, see at Figure 1.

Figure 1: Marketing management in financial institutions Example procurement equipment

MARKET SEGMENTATION AND CUSTOMER ANALYSIS OF INSTITUTIONAL SECTOR Market segmentation [14, p.136] is the process of identifying significant differences in the characteristics of the customers in order to divide the market into two or more groups of consumers for the purpose of: 1) The election of those parts of the market that the company that handles and 2) the creation of products and programs to meet the different needs of each customer group. The Journal of Applied Engineering Science 14(2016)1, 369

benefits of market segmentation [19, p.113-145] strategy are multiple: 1) To better identify marketing opportunities; 2) makes it easy to customize the marketing mix to target specific groups of consumers; 3) helps to better allocate marketing resources; 4) directs the positioning of the product to the consumers, and to competition; 5) directs the planning product development. Market segmentation is desagregate and indicates that there are different demand curve 171

Nada Vignjevi - or evi - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

where until recently it was assumed that there is only one. In a strategy to differentiate the company is trying to control the market and isolate their products from price competition from other companies, using very intensive promotion as a marketing instrument. Segmentation strategy based on the heterogeneity of the market and the fact that there are a number of smaller homogeneous markets due to different consumer preferences.Segmentation as a strategy of adopting products to the needs and demands of customers. Strategy of segmenation is winning market depth. In order to create a market segmentation strategy to ensure it is necessary to do more activities and bring a greater number of decisions. Activities begin with the identification of the dimensions of market segmentation, to create the relative profiles of market segments on the basis of these activities provide for total market potential for each segment. Within each segment to identify the factors of competition, and then define the marketing mix for serving each segment, offering its full range of insurance products were often going in banking business. Marketing environment consists of external factors [3, p. 31-37], which directly or indirectly affect the purchase of the inputs and generate outputs. Marketing environment can be understood as a set composed of six categories of power: political, legal, regulatory, social, economic and technological. Regardless of whether you are changing fast or slow, power environments are always dynamic. For insurance companies changes in the environment creates uncertainty, threats or opportunities. Easy future is not entirely predictable, companies can evaluate what is going to happen. It is safe to say that the same will continue modifying their marketing strategies in response to a dynamic environment. Marketing directors in the insurance companies [20, p.264-285] must be ready not to miss changes in the forces of the environment and to take advantage of opportunities and be prepared when the disadvantages environment, otherwise the company can be found in big trouble. Environmental analysis is the process of evaluation and interpretation of information obtained from market research. The management of the company evaluates.information.concerning.the.accuracy,. trying.to.solve.the.inconsistencies.in.data. Establishe significance of certain findings: Re172

configuration, download, connection pooling and insurance companies through capital competition faced with various forms of non-capital growth and enterprise development. The globalization of business activity favors the establishment of various joint venture investments and strategic alliances in order to take advantage of opportunities in the regional market. Resistance of top management changes [7, p.13-18] may represent one of the major obstacles to the successful implementation of a transformational process. There are a number of reasons, especially in our country, which is why top management does not undertake changes. Some of the most important are: fear of change, whereby the process of managing changes immanent resistance, which is a result of fear of the unknown and experiencing changes as a threat and a possible source of uncertainty; Management is not aware of the business situation of the insurance companies, because the maintenance and improvement of competitive advantage depends primarily on the ability of timely detecting and understanding changes in the external environment, Wrong to interpret or ignore the available information, as insufficient transparency changes may have resulted in basis in the assessment of the current situation; There are no clear vision and strategy for the transformation process, because leadership is a critical factor for the success of management changes which practically means that the leader who recognizes the need for the change and questions the basic assumptions about business and the functioning of the company; Interest in maintaining the current situation because it means a loss of privileges or conditions in our retention of the existing situation allows you to get over the private sector and through various forms of non-institutional privatization achieve significant revenues; The management of insurance companies [2, p.21-25] should not be too much time devoted to operational issues, keeping in mind, everyday ways to review the functioning of the company, that management by listed companies most part of the time is spent removing crisis, emergency situation, which means that management actions aimed at eliminating the evident crisis situation and less the timely warning of opportunities and threats: The success of the past can be a cause Journal of Applied Engineering Science 14(2016)1, 369

Nada Vignjevi -Â orÂ?evi - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

of blindness in the current situation, because of the modern insurance company requires not only adequate sensitivity and speed of reaction to changes already and start the changes through innovation; Not understanding the insurance companyÂ&#x2019;s mission, its competence and the basic ways to achieve competitive advantage, because each company a kind collection of unique resources and the capabilities that provide the basis for a competitive advantage and strategy. Companies must decide precisely how and where to channel your product or insurance products in selected market segments. The needs and desires of the insured in the target markets must be materialized in the form of a marketing mix. It is particularly important to the insured experienced service insurance and how it is positioned relative to competitive offerings. Through analysis, marketing director of the company seeks to describe the current changes in the environment and those anticipated in the future. By evaluating the change manager should be able to identify possible threats and opportunities related to fluctuations in the environment [18, p.74]. Understanding of the current situation and taking into account the threats and opportunities arising from changes in the environment, helps marketing directors in ensuring that assessment actions undertaken and the results of marketing efforts to present and develop marketing strategies for the future. In dealing with the forces in the marketing environment, can be applied to two general approaches: accept power environments like those that can not be controlled, or to confront them and try to shape them. If the power of the environment are viewed as the same, which is impossible to control, the company remains passive and reactive to the environment. Instead of trying to influence the strength environments, its directors seek marketing and factors affecting the expected service as propaganda, oral propaganda and previous experience. External marketing has a direct impact on the promotion of insurance services and indirectly - by tailoring service offers insurance in accordance with the requirements and desires of the insured and the creation of marketing mix on previous experience and oral propaganda. Given that the indirect impact of the consequences of previous results, it is based on realistic possibilities and Journal of Applied Engineering Science 14(2016)1, 369

capabilities of the company, which affects the formation of previous expectations and in most cases is completely objective. Promoting the services offered by the company directly affects the formation of previous expectations. What is the level of the previous expectations of higher quality to be higher, to get it insured and those perceived. Increase expected implies the necessity to improve performance objectively measured by quality, to the perceived quality was higher. Otherwise, the insured tend perception of low quality, even in conditions where it is objectively measured quality satisfactory. The reason lies in the fact that they are not fulfilled (unreasonably) high expectations (actually at the same time is less and the initial inclination of the potential of the insured to conclude insurance, but higher his revolt when they realize that the quality of services delivered is not at the level of promises). Wrong is the determination of those insurance companies that are prone to stress the major communicating the benefits and superiority over the competition, as the expectation of greater created, the greater the danger of a final impression of poor quality. Forming a community risk is a basic assumption of the existence of insurance. Members of the community risk (companies, banks, cooperatives, private individuals) each associate in order distribution of risks, and for common security against unpredictable events, lie of the same risks that threaten them. By forming a community risk is observed that the basic motive of purchase of insurance by the insured person providing the possibility of occurrence of adverse events and other equally important motives such as: security, confidence and protection. The behavior of the insured affects a whole range of factors which may be psychological in nature. Environmental factors of a psychological nature: cognitive behavior, and affective behavior. Cognitive behavior implies the process of receiving information to reaction specific problem. The starting point of knowledge, thinking and beliefs, which are formed under the influence of experience and are stored in the memory of consumers. Environmental factors that can have various forms of influence on the behavior of the insured, the culture, the family, reference groups, social classes and strata, status, lifestyle, etc. These 173

Nada Vignjevi - or evi - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

factors may affect both cognitive and affective system of the insured, and its behavior. Culture has a basic and broadest impact on people s behavior as consumers. Culture defines models of behavior, rules, customs and norms which its members adhere. In those countries where there is a tradition of culture of insurance, there is also the most developed insurance market and vice versa, unfortunately in our country, the culture of the insured is at a low level of objective and subjective reasons. Reference groups are groups whose behavior is a person s reputation. The family is the primary reference group. It affects a number of ways to the formation of values, beliefs and behaviors of individuals and by economic status, emotional support, socialization of children and lifestyle. These are some of the most influential sociological factors that influence the behavior of the insured. From the macroeconomic factors most influential on the behavior of the insured are: national income, social organization, and regulation. The higher national income and higher standard of living and thus a greater need for insurance. STRATEGIC MARKETING MANAGEMENT OF FINANCIAL INSTITUTIONS The first phase of value creation and flow delivery option values as a task of strategic marketing of financial institutions. Segmentation, targeting and positioning are the essence of strategic marketing. Creating and communicating values are a matter of tactical marketing. The space between the marketing strategy and the insured person to whom it is directed, and is filled with tactical activities. The aim of marketing strategy [14, p. 36] may be to increase profitability (increased sales of insurance policies already existing policyholders - increasing customer loyalty) and increasing market share in existing markets or new or both markets (attracting new contributors). Also, target marketing strategies institutions can be both of these merged into one which is generally the practice. Before formulating the objectives of the marketing strategy, according to which it would be directed segmentation, targeting and positioning, it is necessary situational analysis of financial institutions. Situation analysis provides relevant information on the sale of insurance policies, the cost of the 174

insurance companies, competitive insurance companies and a variety of factors in the macroenvironment. Then, market data, as defined. Strong market position means that companies have a large market share and are usually profitable. It is thought that the market share is usually not required to generate profitability. Profitability is a result of business strategies, such as providing high quality insurance services, etc. providing superior insurance services from competitors leads to greater loyalty of the insured, whereby the company will have fewer costs about attracting new customers, which will lead to profitable operations. Profit impact on marketing strategy (PIMs), is not only used to diagnose problem areas or recognition of opportunity, but also to assist in the allocation of resources among business units. PIMs can marketing directors of insurance companies that serve as the formula of success or prescribed guide for guaranteed successful strategic action plans. These models are a supplement, not a substitute for your own judgment marketing director. Characteristics non-financial companies in the business of insurance relating to the internal organization of the work itself which includes the internal marketing. Basic characteristics of the non-financial business relating to the functioning and internal benchmarking, whose focus is to compare the specific activity of the product, service, logistics and other top organizations independent of the type of activity. Internal benchmarking is very interesting for companies that have jagged organizational structure. Given the fact that the insurance company characteristic structure in the form of territorial dislocated organizational units in the form of branches, where the business makes a similar set of operations that can be a very simple way to compare, recommended intensive use of benchmarking for insurance companies. For example, the insurance company that has branches in various regions can be compared to work in them, in order to find the best practical solution, which provides a distinctive quality to the customer s insurance products or identify potential savings. Branch insurance companies we considered strategic business units defining the research of the insurance market: The database includes diagnostic and prescribed information to help in the analysis of marketing activity and formulating marketing strategies. The analysis focuses on the opportunities, issues, Journal of Applied Engineering Science 14(2016)1, 369

Nada Vignjevi - or evi - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

resources and opportunities [4,13]. Contents of market research that should help the insurance company when choosing strategies, identified more than thirty facts that affect the company s operations, and the same would comprise the following: - -Shares in relation to the largest competitor - -The quality of the product compared to the competition - -Rates in comparison with the competition - -Marketing efforts against the competition - -Models of market segmentation - -The rate of introduction of new products - -The structure of the production process - -Capital intensity - -The degree of vertical integration - -Capacity utilization. The productivity of capital equipment, the productivity of employees, budgets research and development, advertising and promotion budgets. These facts can be divided into three sets of variables: (1) those related to the structure of the markets in which the company competes; (2) that describe the company s competitive position within that market; (3) relating to the strategy chosen by the company. The criteria based on which form segments related to the fundamentals of segmentation consists of several groups, the most important are the following: The first group consists of the most commonly used criteria subgroups, which are related to the geographic location makes the buildings and customers on their demographic characteristics related to: age, gender, income, family life cycle, etc. It is the segmentation criteria, which are the simplest and for which data are generally available in all statistical sources secondary data. However, what makes them easily accessible, while placing them in a group of necessary but not sufficient conditions for the realization of the segmentation and the formation of segments. Some authors call them skeleton - skeleton segmentation which must be supplemented by other criteria, primarily those from the group of consumer behavior. Different customer preferences open problem of defining the service offers a variety of market segments, therefore, it is appropriate on the basis of information on the benefits that customers Journal of Applied Engineering Science 14(2016)1, 369

want and expect from a market segment based on criteria from the group of consumer behavior: - Uses required by the service, - Expectations, - Tendency towards building long-term relationships, - Willingness to engage in the process of providing services - responding to marketing factors (factors of supply) - the volume of transactions. EXAMPLE: To define market segments is carried out market research related to qualitative research, focus group discussions, groups of 610 participants, duration of 90-120 minutes. This technique allows a deeper understanding of the behaviors, attitudes, motives, etc. the insured, as well as the collection of large quantities of information in a relatively short period of time. Results of focus group discussions can not be generalized to the population, because the sample is too small. Taking into account that the subjects chosen to advance to the selected criteria, opinions should be considered typical only for this specific segment of the population: the aim of the research: examining the attitudes of participants towards insurance companies. Specification of objectives: 1) Knowledge and attitudes towards different types of insurance, 2) The use of and satisfaction with services insurance house, 3) 3) Trust in the various insurance companies: private / public, domestic / foreign, 4) The perception of the ideal home insurance, 5) The method of information about insurance companies, 6) Perception of individual insurance companies. The insurance company can choose between three alternative strategies align its resources with potential markets: 1) Mass market strategy; 2) The strategy of concentration on one market segment, and 3) multiple market segmentation strategy. Strategy or the so-called mass market undifferentiated marketing response when the market is homogeneous in its demands. With one combination of marketing mix, based on a single product, the company strives to meet the needs of all customers. This strategy is very diffi175

Nada Vignjevi!-"or#evi! - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

cult to perform in the insurance market, primarily because it is not homogeneous in its demands. The strategy of concentration on one market segment concentrated marketing strategy is appropriate when there is a well defined group (segment). The company produces one marketing mix for the special needs of one segment of the target from several market segments; it is one brand of products or services tailored to a group of consumers. Competitive advantage is gained specialization or uniform - a good marketing mix adjustment needs of the target market segment. This segmentation strategy is very present in the insurance market (pension insurance, voluntary health insurance, life insurance, etc.). The strategy assumes multiple segmentation orientation in several market segments to form a marketing mix for each segment individually. The company uses the differences between market segments, trying to achieve maximum participation in the market. The company needs to have great sources. Create different frames for each price segment. This strategy of segmentation in the insurance market can only carry out a large insurance company. Branch insurance companies we considered are strategic business units. The model is applied and the analysis was made on the case following the Balkan countries: Bosnia and Hercegovina, Serbia, Montenegro and Macedonia. Market segmentation is an activity that precedes the selection of target markets, maximizing long-term workload, long-term increase in profit maximizing short-term workload, increase short-term profits, affects the organizational image, the reasons for the offensive strategy for defensive reasons stgrategy, internal resources / capabilities, relative readiness tender, etc. The attractiveness of the segments are classified into several groups: First growth rate - the average annual speed of growth of income sources used by that segment. It can be used and the overall average rate of growth. Of course, when determining the rate of growth of the segment, to be taken into account as much (or not) stimulating business environment. Available second segment size - One way to calculate is to estimate the total income of this segment during the specified time, less inaccessible income, regardless of the invested funds. The second most common way is to use the size 176

of the entire segment, it does not mean that the manager brings any court, which could distort the real picture. This method is recommended. Third potential profits - it is much more difficult to calculate, due to significant fluctuations depending on the segment. For example, for the evaluation of potential profit segment can be used PorterÂ&#x2019;s model of five factors, such as the Table 1. Table 1: Porters model a factor of five Subfactors potentials Rang segment profit 10 = small and 0 = large Pondering subfactor points pondering subfactors (rank x pondering value) 1 Competitive power and cleanliness 2 Risk of supstitute

3 Risk from sojourned

4 Power of suppliers

5 Power of buyers

Points a factor of profit potentials Provenance: M. McDonal, L. Dunbal, Segmentation Marketplace (Market Segmentation), Clio, Belgrade, 2003, p. 136

Subfactors are supstitutes to profit potential is. Pondering value added up to 100 to get ponts a factor of profit potentials. EXAMPLE: In the insurance case, subfactors can be, as the Table 2. Table 2: Porters model a factor of five different services Subfactros Rank segment Pondering large, medium, small x value points pondering Unmet needs for insurance service efficiency 35 Unmet needs for Favors insurance certainty 35 Potential is the price

Competitive cleanliness

Costs of entry to segment

Total: 100 Origin: Research by authors

A factor of three groups (growth variable and obtain it) could be a hundred regards, market insurance to add, for example, political risk and political elements of the municipality. For in-law a factor of attractiveness of the segment pondering the relative greatness to one another, according to specific requirements of insurance company, as the Table 3. Journal of Applied Engineering Science 14(2016)1, 369

Nada Vignjevi!-"or#evi! - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

Table 3: Segmentation of insurance market and profit potential Growt rate

Accessible size segment Profit potential is

Total: 100 Origin: Research by authors

In some coincidences, it can be, to get to pondering growth (That need to small other sentences). Elements of these, may form the combination with a specific market elements of. CONCLUSION In the current extremely difficult economic conditions, onset of the global economic and financial crisis, financial liquidity, declines in economic activity and in connection with this great fall collection of value added tax and other public revenues, severely affected regular functioning of the public sector. Current efforts towards improving marketing management strategies practices constitute an unavoidable aspect of the transition process, as they are directed towards cristaling legal and regulatory framework, building confidence among domestic and foreign investors and strengthen financial markets and banking system. The regime of movement of foreign capital is arranged a series of regulations. Of particular importance are: the Law on Foreign Investment, the Law on Securities Market and Other Financial Instruments Act, the credit relations with foreign countries, the Foreign Exchange Act, the Payment System Act, the Act on Investment Funds. After more than deceide transitional process, Serbia has largely succeeded in introducing the key legal and economic institutions of the market economy. Stability of a financial system depends on the ability of the system to respond to the demands of time in which to exercise its functions. If these functions are not in fully implemented in the laws and regulations governing the financial system of a country, it is understandable that there is a need for such legislation and such a system to be aligned with the current needs and requirements of the financial markets. All the major part of savings managed by institutional investors. Savings realized the benefits of financial innovation, which have significantly lowered the cost of the invested money management services and improve the quality and diversity of investments. This Â&#x201C;gathJournal of Applied Engineering Science 14(2016)1, 369

eringÂ&#x201D; individual savings, have improved the efficiency frontier relations income-risk and on the other hand, over-sized achieve the economies of scale transactions. Also, depositors can expect a higher level of revenues for the same level of risk. Preserving the integrity of the market it is imperative that the occurrence and behavior of all participants, institutions, capital markets, economy, various occupations and professions. Upgrading the regulatory framework in discovering and sanctioning of occurrence as well as training in this area should be part of regular professional development to state control bodies, self-regulatory bodies and brokers, and other professionals associated with the capital market. Also, technical development requires special attention of all participants in the market due to the fact that it opens up new possibilities of abuse, but also new tools for their timely sanction. Continuous education should be a mandatory part of the profession of financial market participants. REFERENCES 1) A Critical Review, (2003). OECD Development Centre, Technical Papers No. 210, p. 31-38 2) Arens A, Elder R, Beasley M, (2003), Auditing and assurance sevices, Prentice Hall, Pearsons Education International, New Jersey, p. 21-25 3) Mark Beasley, Auditing and assurance services, Ninth Edition, Prentice Hall, Pearsons Education International, New Jersey, p. 3137 4) Bergbrant M C., Campbell K T., Hunter D M., Owers J E., (2016), Does Deposit Insurance Retard the Development of Non-bank Financial Markets? Journal of Banking & Finance, Available online 8 February 2016, doi:10.1016/j.jbankfin.2016.01.013 5) Bofinger, Peter and Wollmershauser, (2011), Is there a third way to EMU for the accession countries?, www.uni-magdeburg.de, retrieved on August 30 th, 2014 6) Council Regulation, EC, No 2007/2000. 7) Davis G. And Useem M., (2003), Top Management company Directors and corporate Control, pettigrew and Wittington, .p. 13-18 8) Frey R, Kerl C (2015), Multinational banks in the crisis: Foreign affiliate lending as a mirror of funding pressure and competition on the 177

Nada Vignjevi!-"or#evi! - Standards and competencies of the EU-the market strategies of financial services in the Balkan region

internal capital market, Journal of Banking & Finance, Volume 50, January 2015, Pages 52 68 9) Jeswald S. W. (2002), Corporate Governance in The UNECE Region, UN/ECE, Geneva, 36, p. 17-21 10) Frommel Michael, Volatility Regimes in Central and Eastern European Countries, (2006), www.wiwi..uni-hannover.de, retrieved on September 15 th, 2013 11) Keller, K. L. (2006), Marketing Management, Data status, Belgrade p. 36 12) Lanning MJ and Michaels EG, (2003), A Business is a Value Delivery System, Clio, Belgrade, p. 74 13) Magretta Joan Understanding Michael Porter: The Essential Guide to Competition and Strategy Hardcover December 6, 2011 by Publisher: Harvard Business Review Press; 1 edition (December 6, 2011), 256 pages 14) McDonal L. Dunbal M., (2005), Market Segmentation, Belgrade, Clio, p. 136 15) M. Beer and N. Nohria, (2005), Cracking the Code of Change, Harvard Business Review, May-June, p. 49-61 16) OECD, Organization for Economic Cooperation and Development. [Online] Available: www. oecd.org., retrieved on October 3 th, 2015

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17) Tondl G., (2003), Regional Policy in the boock: The Economics of the European Union Policy and Analysis, Third Edition, Edition by Mike Artis, Frederick Nixson, First Published, New York, p. 123-141 18) ICC, International Chamber of Commerce. [Online] Available: http://www.iccwbo.org/, retrieved on January 10 th, 2016 19) Vignjevi!-Djordjevi! N, (2005), Marfin marketing in finance, Belgrade, Europress, p. 113-145 20) Vignjevi!-Djordjevic N, Zarkovi! N, (2010), Insurance law, institutions, management, Belgrade, Finegraf, p. 264-285 21) Vignjevi! - "or#evi! N. (2009). Corporate governance and regulation the development of public property, competitiveness and transparency of the market. Association of Economists of Serbia, Kopaonik Business Forum, p. 97-112 22) Vignjevi! "or#evi! N., (2014) Corporate governance: state and trends in the region a regulatory approach, Ekonomika preduze!a, UDC 65, YEAR LXII, september-october 2014, pp 264-280 ISSN 0353-443X Paper sent to revision: 24.01.2016. Paper ready for publication: 15.03.2016.

Journal of Applied Engineering Science 14(2016)1, 369

Original Scientific Paper

doi:10.5937/jaes14-10448

Paper number: 14(2016)1, 370, 179-184

DESIGN OF A COMPRESSION STRUCTURE WITH INNER RIBS USING FORCE DENSITY METHOD & TOPOLOGICAL MAPPING Manuel Alejandro Fernández Ruiz* Department of Structural Mechanics, University of Granada, Spain Luisa Maria Gil-Martin Department of Structural Mechanics, University of Granada, Spain Compression-only structures can be modelled as pin-jointed networks with all the members in compression. The final shape of the network can be computed using the Force Density Method (FDM) together with Topological Mapping (TM), introducing the self-weight iteratively until the equilibrium is found. One of the input parameters of FDM is the force-length ratio q of each member of the network. Members with a high q carry a higher level of loads, working as ribs of the structure. The designer defines the proper distribution of the ribs in the network, resulting in aesthetical final shapes. Here, a two-storey compression structure with inner ribs has been designed using TM-FDM. Key words: Compression structures, Force Density Method, Topological Mapping, Form-finding INTRODUCTION The Force Density Method (FDM) first introduced by Schek [01 03] is a method used to solve the form-finding problem of pin-jointed networks. Pin-jointed networks are composed by nodes or joints and members. These members can be in tension (cables) or in compression (rods). The main input of FDM is the force-length ratio or force density q. The equilibrium equations of the network are linearized introducing given values of q for all its members. The inputs of the FDM are: the coordinates of the fixed nodes (supports), the force-length ratio of each member, the connectivity between the nodes and the external forces. Other form-findings methods can be seen in [04]. Topological Mapping (TM) introduced by Hernández-Montes et al. [05,06] is a mapping method that generate a network based on a set of topological rules defined by the designer. An initial geometrical guess of the final equilibrium form of the network is needed to start the form-finding procedure if TM is not included in FDM (TMFDM [01 03,05,06]). Compression structures can be designed using TM-FDM as pin-jointed networks with all its members in compression. FDM was initially conceived for the design of tension structures, being its self-weight negligible. However, the

self-weight of compression structures cannot be ignored. In Carbonell-Márquez et al. [07] the selfweight is introduced as external forces in FDM. By doing so the linearity of the equilibrium equations of FDM disappears because the weight of the structure depends on its final shape. The linearity of the equilibrium equations is restored following the iterative procedure proposed by Carbonell-Márquez et al. [07]. This procedure is inspired in the hanging models used by the famous Spanish architect Antonio Gaudí (18521956) [08]. The tension structure is computed using TM-FDM and the inverse is the compression-only form. The designer assigns the force-length ratio value to each member of the network. Members with a high q carry a higher level of loads, working as ribs of the compression structure. The process of assignation of a q value to each member of the network is directly related with the final shape of the structure, largely because as it has been said previously the form-finding procedure carried out in TM-FDM is similar to the hanging chain models employed by Antonio Gaudí. The proper distribution of ribs in the mesh by the designer can result in aesthetical final shapes. Here, a two-storey compression structure with inner ribs has been designed using TM-FDM. The ground floor has an asymmetrical plan view and it has a series of arches in the contour with

*Department of Structural Mechanics, University of Granada,Calle Real de Cartuja, 36. Granada 18012, Spain; malejandrofr@ugr.es

179

Manuel Alejandro Fernandez Ruiz - Design of a compression structure with inner ribs using force density method and topological mapping

a central hole that works as a skylight. The top floor also has an asymmetrical plan view and it is connected to the ground floor in four points. FORCE DENSITY METHOD The FDM is a method for networks analysis. The equilibrium of pin-jointed networks is solved by means of a single system of linear equations. Here, the same terminology as found in [02] is used. A general network is composed by nt nodes and m members or branches. The nodes that have fixed coordinates are called fixed nodes (acting as supports) and the others are called free nodes. The coordinates along the x, y and z directions of the nodes are collected in the following vectors: x = [x1, , xn]T, y = [y1, , yn]T and z = [z1, , zn]T for free nodes (being n the total number of free nodes) and xf = [xf1, ,xnf]T, yf = [yf1, , yfnf]T and zf = [zf1, , zfnf]T for fixed nodes (being nf the total number of fixed nodes). ( )T represents the transpose operation. The length li and the internal force si of each member are collected in the vectors l = [l1, ,lm]T and s = [s1, , sm]T respectively. The

force-length ratio vector is defined as qj = sj / lj for each member of the mesh. All the q values are collected in the vector q = [q1, , qm]T. Finally, vectors Px = [p1x, , pntx]T, Py = [p1y, , pnty]T and Pz = [p1z, , pntz]T collect the external forces applied in each node in each direction. The connectivity matrix CS is a m×nt matrix that describes the connectivity between all the nodes of the mesh. It is constructed in the following way: if a member j links the nodes i(j) and k(j), with i < k, the ith and kth elements of the jth row of CS are set to 1 and -1 respectively: (1)

In the original method [02] the fixed nodes were taken at the end of the sequence, partitioning the connectivity matrix into two parts CS = [C , Cf]. C(eRmxn) and Cf (eRmxnf) describe the connectivity between the free and fixed nodes respectively (see the example of Figure 1).

Figure 1: A two dimensional pin-jointed structure and its corresponding connectivity matrix CS [C,Cf]. Adapted from [02]

The equilibrium equations of a general pin-jointed network (sum of all the forces applied in each node equal to zero) are the following:

(2)

Where Q is the diagonal matrix of q. 180

TOPOLOGICAL MAPPING One of the main inputs of FDM is the connectivity matrix C. Hernández-Montes et al. [05, 06] proposed a method called Topological Mapping (TM) to construct C. This method creates meshes of triangles based on topology without considering the final equilibrium position of the nodes. The inputs of TM are the number of steps N, the number of nodes of the first step Nni, the type of network (open or closed) and the topological relation between consecutive steps. Journal of Applied Engineering Science 14(2016)1, 370

Manuel Alejandro Fernandez Ruiz - Design of a compression structure with inner ribs using force density method and topological mapping

TM provides three different types of relation between consecutive steps: A, B and C. In all of them the nodes of a given step are connected with the adjacent ones (these members are called here step members). Besides that each node of a given step is connected with three, two or alternatively one or three nodes of the next

step for types A, B and C respectively (these members are called here radial members). In a closed mesh the contour of the final shape corresponds to the nodes of the final step (see Figure 2). On the other hand, in an open mesh the contour of the topological mesh corresponds to the contour of the final shape (see Figure 2).

Figure 2: Types of meshes: closed (a) and open (b). Adapted from [07]

The topological relationships A, B and C can be combined forming a topological sequence (for example C-B-A-A). In a mesh of N steps the topological sequence must contain N-1 letters (A, B and C). FORM-FINDING PROCEDURE The form finding procedure followed in this work is the proposed by Carbonell-Márquez et al. [07]. The self-weight vector Pz,w = [p1z,w, , pntz,w]T is introduced in FDM in the z-direction:

(3)

This vector depends on the position of the nodes. The self-weight of the structure ! is expressed in force by units of area. The members that compose the ribs have a higher weight, so a linear self-weight expressed in force by units of length " is also defined. Finally, the component i of Pz,w is calculated as the summation of the half of the weight of every member that has node i as vertex and is part of a rib and one third of the weight of every triangle that contains the node i as vertex. Journal of Applied Engineering Science 14(2016)1, 370

The system of equations shown in Equation 3 is not linear due to Pz,w. Despite this, the equilibrium equations are solved linearly by iterations [07]. TWO-STOREY COMPRESSION STRUCTURE WITH INNER RIBS A two storey compression structure with inner ribs has been computed following the procedure proposed by Carbonell-Márquez et al. [07]. For both ground and upper floors ! = 1 kN/m2 and " = 1 kN/m. The ground floor is an open mesh with a central hole that works as a skylight. The open mesh has 51 steps (N = 51) and the initial step has 50 nodes (Nni = 50). Type C has been used for all the steps because for this type of relationship the number of nodes of each step remains constant (in the others the number of nodes increases from a step to the next). This means that the topological sequence is C C with a total of 50 C. The coordinates of the fixed nodes (supports) are listed in Table 1. The final equilibrium form of the mesh of the ground floor is shown in Figure 3 together with the q vector used (distribution of ribs). This final shape of the ground floor has not been computed separately from the upper part: the whole structure is computed together, but for a better viewing of the ground floor it has been shown isolated. 181

Manuel Alejandro Fernandez Ruiz - Design of a compression structure with inner ribs using force density method and topological mapping

Table 1: Fixed coordinates of the ground floor x (m)

y (m)

z (m)

2,31

3,26

0,00

3,76

1,81

0,00

6,00

0,80

0,00

7,96

0,71

0,00

9,43

1,27

0,00

2,23

4,68

0,00

3,79

5,19

0,00

5,99

5,72

0,00

8,19

4,36

0,00

9,52

2,57

0,00

Figure 3: Final equilibrium form of the ground floor mesh and distribution of the ribs

On the other hand the upper floor is a closed mesh with 11 steps. The initial step has 32 nodes and type B has been used for all the steps (the topological sequence is BÂ&#x2026;B with a total of 10 B). This part of the structure has not fixed nodes; it has four connections (nodes in common) with the ground floor. The final equilibrium form of the 182

mesh of the upper floor is shown in Figure 4 together with the q vector used. Figures 5 and 6 show different views of the final equilibrium form of the whole structure. Ribs have been highlighted in order to better understand the structural behaviour of the final shape. Journal of Applied Engineering Science 14(2016)1, 370

Manuel Alejandro Fernandez Ruiz - Design of a compression structure with inner ribs using force density method and topological mapping

Figure 4: Final equilibrium form of the upper floor mesh and distribution of the ribs

Figure 5: Two-storey compression structure computed using TM-FDM: general (left) and plan (right) views

Figure 6: Two-storey compression structure computed using TM-FDM: detail of the upper floor (left) and a general view of the skylight (right) Journal of Applied Engineering Science 14(2016)1, 370

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CONCLUSION

REFERENCES

The iterative TM-FDM form-finding procedure proposed by Carbonell-Márquez et al. [07] is a powerful tool for the design of compression structures. Inner ribs can be defined as members with a high force-length ratio. A complex two-storey compression structure with inner ribs has been designed. It presents a combination of closed (ground floor) and open meshes (upper floor). In addition to this, the ground floor has a skylight, highlighting the design flexibility of TM-FDM.

1) K. Linkwitz, H.J. Schek, Einige Bemerkungen zur Berechnung von vorgespannten Seilnetzkonstruktionen, Ingenieur-Archiv. 40 (1971) 145 158. 2) H.J. Schek, The force density method for form-finding and computation of general networks, Comput. Methods Appl. Mech. Eng. 3 (1974) 115 134. 3) K. Linkwitz, About form-finding of doublecurved structures, Eng. Struct. 21 (1999) 709 718. 4) D. Veenendaal, P. Block, An overview and comparison of structural form finding methods for general networks, Int. J. Solids Struct. 49 (2012) 3741 3753. doi:10.1016/ j.ijsolstr.2012.08.008. 5) E. Hernández-Montes, R. Jurado-Piña, E. Bayo, Topological Mapping for Tension Structures, J. Struct. Eng. 132 (2006) 970 977. 6) R. Jurado-Piña, L.M. Gil-Martín, E. Hernández-Montes, Topological mesh for shell structures, Appl. Math. Model. 33 (2009) 948 958. doi:10.1016/j.apm.2007.12.018. 7) J.F. Carbonell-Márquez, L.M. Gil-Martín, M.A. Fernández-Ruiz, E. Hernández-Montes, Topological design of compression structures, Arch. Appl. Mech. (2015). 8) S. Huerta, Structural design in the work of Gaudí, Archit. Sci. Rev. 49 (2006) 324 339. Paper sent to revision: 04.02.2016. Paper ready for publication: 07.03.2016.

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Prof. dr Milo Kne evi UVODNIK

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REZIMEI RADOVA Vlastimir Radonjanin, Mirjana Male ev, Ivan Luki , Slobodan upi , Suzana Vukoslav evi PROCENA STANJA I SANACIJA MONTA NE AB KONSTRUKCIJE NAKON PO ARA

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Glushkov Alexey Vyacheslavovich, Bartolomey Leonid Adolfovich UTICAJ OBLIKA I VELI!INE IZOLOVANIH TEMELJA NA STRES-DEROMACIONU BAZU TLA

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Jelena Rusov, Mirjana Misita MODEL SISTEMA ZA PODR KU ODLU!IVANJU KORI %EN ZA OCENU RIZIKA

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Filip Zdraveski, Zoran Bogatinoski, Bojana Trajanoska MODELIRANJE SINGLE-FILLET PREKLOPNOG SPOJA U SOLIDWORKS SIMULACIJI

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Y.S.Andrianov, L.M. Nizova, A.S. Nikitina OBUKA IN ENJERSKOG OSOBLJA KROZ PRIMER DR AVNOG UNIVERZITETA TEHNOLOGIJE U VOLGI, MARI EL, RUSIJA

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Mijat Jocovi , Nikola Milovi , Boban Melovi NU NOST REGULATORNIH REFORMI KAO PRETPOSTAVKA DALJEG RAZVOJA GRA#EVINSKOG SEKTORA U CRNOJ GORI

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Maria Francesca Milazzo O ZNA!AJU MENAD ERSKIH I ORGANIZACIONIH VARIJABLI U KVANTITATIVNOJ PROCENI RIZIKA

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Polukhina A.N., Rukomoinikova V.P. RAZVOJ KLASTERSKOG PRISTUPA TURIZMU (RUSKA STUDIJA SLU!AJA)

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Sergei Bovteev, Svetlana Kanyukova, Vladimir Okrepilov, Anna Rezvaia METOD OCENJIVANJA SPOSOBNOSTI ZAVR AVANJA GRA#EVINSKOG PROJEKTA DO UTVR#ENOG DATUMA I KONTROLA KVALITETA

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Vladimir Okrepilov, Marina Gravit, Ekaterina Nedviga, Dudnik Oleg UTICAJ POSLOVNE REPUTACIJE NA REZULTATE DELATNOSTI ORGANIZACIJE GRA#EVINSKE SFERE

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Sanja Paunovi ari , Veljko Radulovi , Ema Alihod i Ja arovi , Vera Murgul SVETLO OTKRIVA ARHITEKTONSKU FORMU - ULOGA SVETLA U SAVREMENIM INTERPOLACIJAMA

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Mladen Perazi , Nevenka Pavli!i , Milo Kne evi POSTIZANJE RODNE RAVNOPRAVNOSTI U OBRAZOVANJU U GRA#EVINARSTVU U CRNOJ GORI

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Mikhail Valerievich Shubenkov, Dmitriy Alksandrovich Khomyakov PROSTRANSTVO REGIONALNIH AGLOMERACIJA I REINDUSTRIJALIZACIJA

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Ana Trombeva-Gavriloska, Marijana Lazarevska, Meri Cvetkovska EKSPERIMENTALNO ISPITIVANJE KOMPOZITNIH SENDVI! PLO!A SA RAZLI!ITIM SPOLJA NIM PLO!AMA

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Nada Vignjevi or evi STANDARDI I NADLE NOSTI EU - TR I NE STRATEGIJE FINANSIJSKIH USLUGA U REGIONU BALKANA

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UVODNIK

I esti put na obroncima perlijepog Durmitora, u martu, odr an je skup Gra!evinarstvo - nauka i praksa 2016. I u godini kada Crna Gora gradi svoj autoput cilj skupa je bio da oblikuje profesionalnu budu"nost graditeljstva. Svijet gra!evinarstva je izazovan i pru a anse i privilegije onima koji se njim bave, ali zahtijeva velike napore i brojna odricanja. Prof. dr Milo Kne evi

Horizonte skupa ovog puta #injelo je 215 radova koje potpusuju autori iz 19 zemalja.

Zahvaljujemo se #lanovima Nau#nog odbora i autorima, a posebno sponzorima i prijateljima, predstavnicima inostranih i doma"ih institucija koji su nas podr ali u organizaciji i pomogli odr avanje skupa GNP 2016. Ovaj broj #asopisa posve"en je odabranim radovima sa Skupa. S po tovanjem, Prof. dr Milo Kne evi Univerzitet u Podgorici, Gra evinski fakultet, Crna Gora, Predsednik Organizacinog odbora GNP 2016

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REZIMEI RADOVA

doi:10.5937/jaes14-6150

Broj rada: 14(2016)1, 346

PROCENA STANJA I SANACIJA MONTA NE AB KONSTRUKCIJE NAKON PO ARA Vlastimir Radonjanin, Univerzitet u Novom Sadu, Fakultet Tehni!kih nauka, Novi Sad Mirjana Male ev, Univerzitet u Novom Sadu, Fakultet Tehni!kih nauka, Novi Sad Ivan Luki", Univerzitet u Novom Sadu, Fakultet Tehni!kih nauka, Novi Sad Slobodan upi", Univerzitet u Novom Sadu, Fakultet Tehni!kih nauka, Novi Sad Suzana Vukoslav!evi", Univerzitet u Novom Sadu, Fakultet Tehni!kih nauka, Novi Sad U radu je data procena stanja i sanacija monta ne AB konstrukcije u Novom Sadu nakon po ara. Rad sadr i rezultate detaljnog vizuelnog pregleda, gde su prikazana i klasifikovana registrovana o te enja i defekti za AB stubove i grede, kontrolu kvaliteta ugra enih materijala, geodetsko snimanje vertikalnosti stubova i zaklju ak o stanju konstukcije. Data su i obrazlo ena dva od nekoliko mogu ih sanaciona re enja. Klju ne re i: AB konstrukcija, Po ar, Vizuelni pregled, Kontrolni prora un, Sanacija doi:10.5937/jaes14-7659

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RAZLIKE U UTICAJIMA TEORIJA DRUGOG REDA U ZAVISNOSTI OD #LANOVA PRESEKA Slavko Zdravkovi", Univerzitet u Ni u, Gra$evinsko-Arhitektonski fakultet, Ni Tomislav Igi", Univerzitet u Ni u, Gra$evinsko-Arhitektonski fakultet, Ni Marina Mijalkovi", Univerzitet u Ni u, Gra$evinsko-Arhitektonski fakultet, Ni Milovan Stanojev, Univerzitet u Ni u, Gra$evinsko-Arhitektonski fakultet, Ni U ovom radu teorija Drugog reda poti e od metoda deformacije. U datim numeri kim primerima (1 i 2) je pokazano da za iste vrednosti normalnih sila u lanovima, za iste du ine lanova sistema i za isti modul elasti nosti E, ali za razli ite dimenzije preseka, se dobijaju veoma razli iti uticaji. Izra unate vrednosti momenata savijanja se veoma malo, ako je presek sistema lan bli e stvarnoj vrednosti, nego ako su lanovi popre nog preseka koji su bli e granici stabilnosti sistema. to je ve a rigidnost lana, to su manje razlike u uticajima i pomeranjima izra unatih u skladu sa linearizovanom i preciznom teorijom drugog reda. Klu ne re i: Teorija drugog reda, !lanovi, Preseci doi:10.5937/jaes14-9136

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UTICAJ OBLIKA I VELI#INE IZOLOVANIH TEMELJA NA STRES-DEROMACIONU BAZU TLA Glushkov Alexey Vyacheslavovich, Dr avni Tehnolo ki Unioverzitet u Volgi, Volga, Rusija Bartolomey Leonid Adolfovich, Dr avni Tehnolo ki Unioverzitet u Volgi, Volga, Rusija Ovaj lanak razmatra istra ivanje stres-deformaciono stanje temel"a pod razli ito ob-likovanim temel"ima. Osnova temelja odlikuje uskla eno i ne kohezivno zeml"i te. Gra evinski propisi ne dozvol"avaju da se vr i procena stres-deformacine baze sa slo enim oblicima temelja. !lanak predstavl"a kvalitativna i kvantitativna stres-deformaciona stanja promene ob-lika u izmenama crte a. Istra ivanje pokazuje pona anje tla pod slo enim oblicima temel"a, komponente pomeranja i izolovanost stresa su tako e predstavl"ene. A pose-bna pa nja je posve ena proceni uticaja skaliranja faktora na stres-deformaciju u os-novi u obliku preseka temelja. Ovaj lanak mo e biti zaniml"iv onima koji rade u oblasti izgradnje konstrukcija i geotehnolo kim in enjeringom. Klju ne re i: Oblik temelja, Krstasta, Oblik krsta, Stres-deformaciona analiza, Faktor skaliranja 188

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MODEL SISTEMA ZA PODR KU ODLU!IVANJU KORI %EN ZA OCENU RIZIKA U OSIGURAVAJU%OJ KOMPANIJI Jelena Rusov, Dunav Osiguranje ado Beograd Mirjana Misita, Univerzitet u Beogradu, Ma inski fakultet, Beograd Za savremeno poslovanje u uslovima neizvesnosti, rezultati predvi anja poslovanja su od su tinskog zna aja za evaluaciju budu e finansijske efikasnosti preduze a. U radu je izlo en primer predvi anja premija na osnovu ocena izvora rizika u osiguranju. Zbog neizvesnosti koja prati trenutak nastanka i iznosa tete neophodno je osigurati dovoljno sredstava za pokri e rizika. Za uskla ivanje sredstava i obaveza potrebno je oceniti uticaj rizika na promenu premije po vrstama osiguranja, to ini osnovni koncept razvoja i poslovanja osiguravaju ih dru tava. U radu je predstavljeno eksperimentalno istra ivanje rangiranja rizika na osnovu projektovanog modela u sistemu za podr ku odlu ivanju. Sistem za podr ku odlu ivanju kori en je u cilju generisanja hijerarhije uticajnih kriterijuma i alternativa u modelu za ocenu rizika kod navedenih vrsta osiguranja. Predlo eni model zagovara ideju da se za vrste osiguranja kod koje se utvrdi najvi i stepen rizika i na osnovu toga donesu odluke o visini premije u narednom periodu. Klju ne re i: predvi anje, AHP, ocena rizika doi:10.5937/jaes14-8900

Broj rada: 14(2016)1, 349

MODELIRANJE SINGLE-FILLET PREKLOPNOG SPOJA U SOLIDWORKS SIMULACIJI Filip Zdraveski, Univerzitet Sv. Kiril i Metodij u Skoplju, Ma inski fakulet, Skoplje, Makedonija Zoran Bogatinoski, Univerzitet Sv. Kiril i Metodij u Skoplju, Ma inski fakulet, Skoplje, Makedonija Bojana Trajanoska, Univerzitet Sv. Kiril i Metodij u Skoplju, Ma inski fakulet, Skoplje, Makedonija Cil! projekta predstavl!enog u ovom radu je da se poka e primenl!ivost SolidWorks Simulation modula za prora un strukturnih zavarenih spojeva. Prezentacija se vr i putem jednostavnog modela aksijalno optere enog jednom letvom preklopnog spoja. SolidWorks Simulacija nudi nekoliko opcija za FEM analizu zavarenih spojeva. Sve razumne opcije su eksploatisane i njihovi rezultati se porede u ovom radu. Referentne vrednosti se koriste za proveru rezultata FEM analize. One se izra unavaju na osnovu formulama opisanim u Eurokod 3 dela 8 koji se odnose na dizajn otpora filea zavarenih spojeva. FEM analiza se vr i u najnovijoj verziji SolidWorks Simulation 2015 i starije verzije 2012. Rezultati dobijeni u obe verzije razlikuju jedni od drugih pod istim po etnim uslovima. Kona no, rad daje preporuke za pouzdanost SolidVorks Simulation da se koristi kao sredstvo projektovanja za prora un zavarenih spojeva. Klju ne re i: Zavarena konstrukcija, Projektovanje otpora zavarenih spojeva, File zavarivanje, Metoda kona nih elemenata (MKE)

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REZIMEI RADOVA doi:10.5937/jaes14-9399

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OBUKA IN ENJERSKOG OSOBLJA KROZ PRIMER DR AVNOG UNIVERZITETA TEHNOLOGIJE U VOLGI, MARI EL, RUSIJA Evgenii Romanov, Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Yuri Andrianov, Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Lyudmila Nizova, Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Anna Nikitina, Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija U ovom radu se ukazuje na prioritete i probleme obuke in enjerskih kadrova kroz primer Volga State Universiti of Technologi, Mari El, Rusija. U lanku su prikazana slede a pitanja: dinamika njenog inovativnog razvoja, interakcija izme u univerziteta i poslodavaca, realizacije strate kih razvojnih programa, inovativne pro irenje infrastrukture, pove anje aktivnosti dru tava nau nih u enika, stvaranje me uregionalnih resursa i jedinstvenih centara zajedni kog kori enja. Na osnovu pra enja, dru tvenih istra ivanja diplomaca-in enjera i intervjua poslodavaca, sumirali smo iskustvo u oblasti interakcije izme u studentskih nauka i proizvodnje, i ta je izazvalo razloge za neravnote om na regionalnom tr i tu rada i na tr i tu obrazovnih usluga. U radu se utvr uje nova dimenzije saradnje izme u univerziteta i preduze a, ukl u uju i i me unarodni nivo. Klju ne re i: In enjer, Nauka, Proizvodnja, Studenti, Institucija viskog obrazovanja, Inovativne metode obuke, Zaposlenje diplomaca, Tr i te rada doi:10.5937/jaes14-9825

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NU NOST REGULATORNIH REFORMI KAO PRETPOSTAVKA DALJEG RAZVOJA GRA!EVINSKOG SEKTORA U CRNOJ GORI Mijat Jocovi#, Univerzitet Crne Gore, Ekonomski fakultet, Podgorica, Crna Gora Nikola Milovi#, Univerzitet Crne Gore, Ekonomski fakultet, Podgorica, Crna Gora Boban Melovi#, Univerzitet Crne Gore, Ekonomski fakultet, Podgorica, Crna Gora U ovom radu autori su istra ivali uticaj kvaliteta pravne regulative na razvoj sektora gra evinarstva u Crnoj Gori. Autori su uo ili i jasno istakli da zna aj gra evinarstva za ukupnu ekonomiju Crne Gore, njegov uticaj na ostale privredne djelatnosti i u e e u dru tvenom bruto proizvodu dr ave u potpunosti opravdava potrebu za konstantnom pa njom kreatora politike. U radu su uo eni i jasno istaknuti klju ni problemi u pravnom okviru koji su negativno uticali na unapre enje konkurentnosti ovog sektora i nacionalne ekonomije. Kao najzna ajniji identifikovani su: trend nestabilnosti propisa, postojanja me usobne kolizije zakona i podzakonskih akata, regulativa prostornog planiranja, izdavanje gra evinskih dozvola, registracije imovine i sistem javnih nabavki. Nakon analize promjena u regulatornom okviru i njihovog uticaja na pobolj anje pozicije Crne Gore na listama konkurentnosti relevantnih me unarodnih organizacija, autori iznose op ti zaklju ak da su nu nost regulatorne reforme uz istovremeno obezbje enje predvidljivog i funkcionalnog sistema jedan od osnovnih preduslova za dalji razvoj ovog sektora. Klju ne re i: Gra evinarsrtvo, Crna Gora, Regulatorne promjene, Gra evinske dozvole, Registracija imovine

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doi:10.5937/jaes14-9842

O ZNA!AJU MENAD ERSKIH I ORGANIZACIONIH VARIJABLI U KVANTITATIVNOJ PROCENI RIZIKA Maria Francesca Milazzo, Univerzitet u Mesini, Mesina, Italija Uobi ajeni postupci za kvantitativnu procenu rizika (KRA) ukl u uju procenu frekvencije izdanja i srodnih po etnih uzroka; oni su u funkciji nekoliko parametara kao to su stope komponente neuspeha, verovatno e l udske gre ke, o te enja opreme i upravl a kih faktora. Dostupnost op tih vrednosti za takve parametre iz literature pojednostavl uje rad analiti ara rizika, ali dati standardizovani rezultatii, na alost ne dozvol avaju uzimanje u obzir specifi nost ove fabrike. Specifi nost osnivanja je definisana kroz svoj sistem upravl anja, tako da su menad erski i organizacioni faktori zanemarilii ili nepravilno ocenjenili analizu rizika za dva identi ne ustanove, koje karakteri e potpuno razli iti sistemi za upravl anje, daje iste rezultate i to se pojavl uje potpuno neprihvatl ivo, posebno kada analiza rizika se koristi za odluke osnovanog rizika. Ovaj dokument ima za cil kvantifikovanje efekata menad erskih i organizacionih varijabli na frekvenciji suzbijanja gubitaka papirologije, koriste i jednostavan i fleksibilan metod koji su razvili Milazzo i koautori u 2010. godini takva metodologija je testirana na novoj studiji slu aja i rezultati procene su potvr ene od obe ta ke u pogledu osetl ivosti i nesigurnosti. Aplikacija je pokazana u pogledu alkilovanja jedinice rafinerije. Klju ne re i: Industrijska bezbednost, Kvantitativna procena rizika, Gubitak zadr avanja, Uzrok neuspeha, Cevovodi, Frekvencija doi:10.5937/jaes14-9932

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RAZVOJ KLASTERSKOG PRISTUPA TURIZMU (RUSKA STUDIJA SLU!AJA) Polukhina A.N., Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Rukomoinikova V.P., Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Koncept grupisanja turizma je trenutno u fokusu razvoja turizma na nacionalnom i regionalnom nivou. Istra ivanje je bazirano na me unarodnom akademskom pregledu literature i analize ruskog iskustva. U radu se analizira dinamika turisti kog potencijala partnerskih regiona koji su u li u klaster Velika Volga (Big Volga), na osnovu stru nog mi l enja. Postoji cost-benefit analiza turisti ke industrije u regionima ukl u enim u turisti ki klaster kor-iste i statisti ke podatke. dijagrami zasnovane analize pokazuju diferencijaciju regiona Volge u smislu potencijal-ne upotrebe turizma. Ekonometrijski pristup je omogu io prou avanje zavisnost turizma potencijalnih pokazatel a o prihodu turisti kog klastera Velika Volga . Rezultati istra ivanja omogu avaju grupisanje regiona ukl u enih u klaster u zavisnosti od efikasnosti njihovog turisti kih potencijala sprovo enja. Istra ivanje tako e pokazuje zna aj evaluacije potencijala komparativnih turisti kih klastera. Komparativna metoda za analizu klaster omogu ava unapre enje razvoja regionalnog turizma. Klju ne re i: Klaster, Strategija razvoja turzima, Sektor turizma, Reginalna ekonomija

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REZIMEI RADOVA doi:10.5937/jaes14-10123

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PRAKTI!NI ASPEKTI REALIZACIJE STRATEGIJE RAZVOJA U PODRU!JU TURIZMA Rukomoinikova V.P., Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Zykova N.N., Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Tumbaeva I.D., Dr avni Univerzitet Tehnologije u Volgi, Mari El, Rusija Mnogi autori su okrenuli istra iva ke interese ka problemu efikasnosti realizacije strategije razvoja turizma. To je rezultat injenice da se pojavl uje rast i sprovo enje razvoja strategije turizma da bude zajedni ki svetski trend u poslednjoj deceniji. Ovo istra ivanje se fokusira na teritorijalnom nivou. U radu se koncentri e na malom prostoru centralnog dela Rusije na primeru koji su autori eleli da do ive realizaciju strategije razvoja turizma usvojenog od strane op tinskih vlasti. Glavni cil ovog istra ivanja ima nekoliko cil eva u vezi sa teorijskom analizom prakti nih aspekata razvoja turizma problema u regionu. Pre svega, postoji potreba da se obezbedi pregled literature posve ene regionalnoj evaluaciji efikasnosti turizma. Drugo, neophodno je meriti turisti ku efikasnost u regionu na kvantitativnom i kvalitativnom nivou. U kvantitativnom nivou odnosno statisti kim podacima o regionalnom turiz-mu. Kvalitativna nivo obuhvata studiju slu aja sa pojedincima samozaposlene koji su osnovali svoj posao u ob-lasti seoskog turizma. Na kraju, ova studija ima glavni cil da identifikuje mogu nosti za turisti ki potencijal malih pol oprivrednih regiona Mari El. Sasvim je trenutno va no za region da otkrije uzorke prema kojem je Insercija privatnog sektora u razvoju seoskog turizma odvija. Istra ivanje je bazirano na me unarodnoj akademskoj literaturi i analizi ruskog iskustva. Klju ne re i: Strategija razvoja turizma, Programi dugoro nog razvoja turizma, Indikatori u inka, Klaster, Turisti ka destinacija doi:10.5937/jaes14-10176

Broj rada: 14(2016)1, 356

OTKRIVANJE SIBILA IROM ZAJEDNICE PREKO SOCIJALNOG INTERNETA STVARI A. Meena Kowshalya, Dr avni fakultet Tehnologije, Coimbatore, Tamil Nadu, Indija M.L.Valarmathi, Dr avni fakultet Tehnologije, Coimbatore, Tamil Nadu, Indija Dru tveni Internet Stvari je nova paradigma koja integri e Internet Stvari i dru tvene mre e. Postoji nekoliko izazova u izgradnji Socijalnog Interneta Stvari (SIoT). Vrlo ograni eno istra ivanje je sprovedeno u poslednjih 7 godina da izgradi pouzdane zajednice Socijalnog Interneta Stvari. Glavna pretnja socijalnom stvarima je Sibil napad. Po to SIoT se sastoji od autonomnog prostora/ vorova, pra enje la nog identiteta je otvoren problem. Ovaj dokument predla e novi mehanizam za identifikaciju Sibila u zajednicama Socijalnog Interneta Stvari. Ovaj rad ima za cil da (I) identifikuje zajednicu izme u Socijalnog Interneta Stvari koje koriste Communiti_Infer algoritam. Koriste i osobine dru tvenih mre a i ACO heuristike razli itih zajednica me u socijalnim Internet Stvarima su identifikovani. (II) zajednice su proverene za postojanje Sibila. Algoritam Detect_Sibil detektuje i klasifikuje broj Sibila u svakoj zajednici. U pore enju sa postoje im planovima predlo en je na in klasifikacije zajednice precizno sa visokim rezultatom modularnosti. Klju ne re i: Ta ka atributa sli nosti, Optimizacija mravlja kolonija, Detekcija zajednice, Detekcija Sibila

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REZIMEI RADOVA doi:10.5937/jaes14-10454

Broj rada: 14(2016)1, 357

KOMBINACIJA FLASTERA I TO!KA OPTERE%ENJA - ANALITI!KI PRISTUP KOP!ANJU PLO!A Olga Miju kovi#, Univerzitet Crne Gore, Gra$evinski fakultet, Podgorica, Crna Gora Branislav "ori#, Univerzitet u Beogradu, Gra$evinski fakultet, Beograd, Srbija Biljana %epanovi#, Univerzitet Crne Gore, Gra$evinski fakultet, Podgorica, Crna Gora Protekle studije o stabilnosti pravougaone plo e pod uticajem promenl ivih optere enja su zasnovane na pretpostavkama simplificiranih stres distribucija, u kojima je pitanje ta nost rezultata dobijenih na taj na in. Postupak primene ta no stresa funkcije u problemu elasti ne stabilnosti plo e sa razli itim grani nim uslovima pod efektima flastera i to ka optere enja je prikazan u ovom radu. Mathieu (1890) dobio je ta no re enje za ravan naprezanja za pravougaoni element za pojedine vrste promenl ivih pritisak na granicama. Pekar al (1993), nakon Mathieu je rezultate, analizirali op ti problem pravougaonog plo e optere ene od potpuno proizvol nim distribucija (normalna i / ili makazama) nagla enim du ivica plo e. Analiti ki pristup se koristi za odre ivanje kriti nog optere enja zasnovan na dobro poznatom energetskom tehnikom Ritz. Energija naprezanja zahval uju i savijanju plo e definisan je na tradicionalan na in. S druge strane, distribucija ta nog naprezanja Mathieu teorije elasti nosti uvodi kroz potencijalne energije plo e povezanog sa obavl enog posla eksternim optere enjem. Rezultati za dobijeno kriti no optere enje predstavl eni analiti kim pristupom potvr eno numeri kim kona nim elementima (FE) radi. Klju ne re i: Elasti na stabilnost plo a, Egzaktna funkcija naprezanja, Flaster i to ak optere enja doi:10.5937/jaes14-10469

Broj rada: 14(2016)1, 358

PROJEKTOVANJE ENERGETSKI EFIKASNIH, ZASTAKLJENIH KONSTRUKCIJA SA KONFORTNOM MIKRO-KLIMOM U SEVERNIM REGIONIMA Viktor Pukhkal, Dr avni Univerzitet Arhitekture i Gra$evine, St. Petersburg, Rusija Andrii Bieliatynskyi, Nacionalni Unoverzitet Avijacije, Kijev, Ukrajina Vera Murgul, Dr avni Politehni%ki Univezitet, St. Petersburg, Rusija S rastom popularnosti objekata sa potpuno staklenim fasadama i krovovima javlja se potreba za dodatnim analizama uslova obezbe ivanja konfortne mikro-klime u njima. Posebnim zadatkom javlja se razrada principa projektovanja staklenih objekata u severnim regionima. U ovom radu su uop teni podatci o temperaturnom re imu u prostorijama i na unutra njim povr inama zastakljenih komercijalnih paviljona, izradjenih od stakla. Navedeni su podatci za projektovanje zastakljenja, koji imaju zna ajne povr ine fasadnog ili krovnog zastakljenja za severni region. Istra ivani su faktori, koji stvaraju ose aj diskonforta kod ljudi u prostorijama sa zna ajnim zastakljenim povr inama. Opredeljeni su toplotni gubitci komercijalnih paviljona sa razli itim odnosima razmera i potro nja energije njihovih sistema grejanja na primeru klimatskih uslova severnog grada Sankt-Petersburga (Rusija). Klju ne re i: Transparentne strukture, Energetska efikasnost, Zgrada, Staklo, Izgradnja

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REZIMEI RADOVA doi:10.5937/jaes14-10470

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ANALITI!KO RE ENJE ZA JEDNOSTAVNE PODR ANE LAMINIRANE KOMPOZITNE PLO!E ZASNOVANO NA PARCIJALOJ LAYERWISE TEORIJI Marina Rako"evi#, Univerzitet Crne Gore, Gra$evinski fakultet, Crna Gora Anizotropni sastav slojeva kompozitne plo e zahteva preciznije matemati ke i kalkulacijske modele. Primenom REDDI teorije layerwise mo emo pokriti irok spektar problema slojevitih kompozitnih plo a sa proizvol nim rasporedom slojeva kroz debl ine. Analiti ki metod re avanja jedna ine savijanja u Layerwise teoriji se zasniva na pretpostavl enom pomeranju pol u u obliku duplog trigonometrijskoj Fourier seriji. Analiti ki rastvor se mo e koristiti kao test rastvor za re enja dobijenim kori enjem numeri ke metode, ukl u uju i metode kona nih elemenata. Za delimi nu Layerwise teorijiu u radu predstavl a jedna ine savijanja za laminirani kompozitne plo e i algoritma za izra unavanje ugiba i napona u proizvol nom preseku jednostavno podr ava pravougaonog plo e optere ene sa raspore enom optere enju. Na osnovu algoritma predstavl enog u ovom radu, autor je pripremio Fortran program pod nazivom ANSLACOP (analiti ko re enje plastificiranih kompozitne plo e), ija struktura e biti predstavl ena u radu. Predstavl eni dobijeni rastvor pomo u ovog programa vrlo brzo konvergira u zavisnosti od usvojenog broja lanova dvostrukih trigonometrijeskih serija. Klju ne re i: Laminirane kompozitne plo e, Sloj, Savijanje, Parcijalna Layerwise teorija, Analiti ko re enje doi:10.5937/jaes14-10471

Broj rada: 14(2016)1, 360

NOSIVOST NA SMICANJE PODU NOG SMI!U%EG SPOJA OSTVARENOG GRUPAMA MO DANIKA Milan Spremi#, Univerzitet u Beogradu, Beograd, Srbija Zlatko Markovi#, Univerzitet u Beogradu, Beograd, Srbija Jelena Dobri#, Univerzitet u Beogradu, Beograd, Srbija Dragan Bu$evac, Univerzitet u Beogradu, Beograd, Srbija Diskontinualan podu ni smi u i spoj ostvaren grupisanim mo danicima sa glavom je esto kori eno konstruktivno re enje smi u eg spoja kod monta nih spregnutih nosa a. Prikazana je primena smi u eg spoja ostvarenog grupama mo danika sa glavom i prora un nosivosti na smicanje, na primeru tipi nih monta nih spregnutih podnih nosa a me uspratnih konstrukcija. Mogu nost i opravdanost primene konstruktivnog re enja smi u eg spoja grupama mo danika su razmatrani. Pokazano je da se smi u i spoj monta nog spregnutog podnog nosa a mo e izvesti grupom od etiri mo danika. Klju ne re i: Monta ne spregnute grede, Smi u i spoj, Grupe mo danika sa glavom

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REZIMEI RADOVA doi:10.5937/jaes14-10473

Broj rada: 14(2016)1, 361

ANALIZA SLOBODNIH OSCILACIJA PROSTORNIH LINIJSKIH NOSA!A RAZLI!ITIH KONTURNIH USLOVA Ljiljana ugi#, Univerzitet Crne Gore, Podgorica, Crna Gora Stanko Br#i", Univerzitet u Beogradu, Beograd, Srbija piro Gop#evi", Visoka elezni#ka kola strukovnih studija, Beograd, Srbija U radu je prikazana analiza slobodnih oscilacija prostornih linijskih nosa a primjenom konzistentne matrice masa, odnosno programa ALIN koji je napisan u programskom jeziku C++. Vrijednosti kru nih frekvencija za prostornu prostu gredu i prostornu uklje tenu gredu, dobijene kori enjem programa ALIN su upore ene sa ta nim vrijednostima, kao i sa vrijednostima dobijenim kori enjem programa TOWER. Da bi se dobili to ta niji rezultati, potrebno je podijeliti nosa e na ve i broj kona nih elemenata. Za razliku od programa TOWER, koji koristi koncentrisanu matricu masa, program ALIN koristi konzistentnu matricu masa, pa podjela nosa a mo e biti krupnija nego pri primjeni programa TOWER. Klju ne re i: Konzistentna matrica masa, Koncentrisana matrica masa, Kru na frekvencija doi:10.5937/jaes14-10443

Broj rada: 14(2016)1, 362

METOD OCENJIVANJA SPOSOBNOSTI ZAVR AVANJA GRA$EVINSKOG PROJEKTA DO UTVR$ENOG DATUMA I KONTROLA KVALITETA Sergei Bovteev, Dr avni Politehni#ki Univezitet, St. Petersburg, Rusija Svetlana Kanyukova, Dr avni Politehni#ki Univezitet, St. Petersburg, Rusija Vladimir Okrepilov, Dr avni Politehni#ki Univezitet, St. Petersburg, Rusija Anna Rezvaia, Dr avni Politehni#ki Univezitet, St. Petersburg, Rusija U radu se rasmatraju principi obezbe ivanja zavr avanja gra evinskih projekata do utvr enog datuma. Predlo ena metodika ocenjivanja progresa projekta i ocenjivanja mogu nosti svojevremenog zavr etka projekta, osnovana je na primeni pokazatelja ScheduleTimelessIndex (STI) i ScheduleProgressIndex (SPI). Metodika dozvoljava dinami no analiziranje otstupanje rokova projekta za operativno dono enje efektivnih upravlja kih re enja. Klju ne re i: Planiranje, Upravljanje projektima, Indeksi performanse, Performanse projekta doi:10.5937/jaes14-10448

Broj rada: 14(2016)1, 370

PROJEKTOVANJE KOMPRESIONE STRUKTURE SA UNUTRA NJIM REBRIMA KORI %ENJEM METODE SNAGE GUSTINE I TOPOLO KOG MAPIRANJA Manuel Alejandro Fernández Ruiz, Univerzitet u Granadi, Granada, panija Luisa Maria Gil-Martin, Univerzitet u Granadi, Granada, panija Struktura samo sa kompresijom mo e da se modelira kao pin-spojena mre a sa svim lanovima u kompresiji. Kona ni oblik mre e se mo e izra unati kori enjem metode snage gustine (FDM) zajedno sa toplo kim mapiranjem (TM), uvo enje sopstvene te ine iterativno dok se ne prona e ravnote a. Jedan od ulaznih parametara FDM je sila-du ina odnos K svakog lana mre e. !lanovi sa visokim k nose ve i stepen optere enja, radi kao rebro strukture. Projektant defini e adekvatnu raspodelu rebara u mre i, to dovodi do estetskih krajnjih oblika. Evo, dvospratna kompresija struktura sa unutra njim rebrima je dizajniran pomo u TM-FDM. Klju ne re i: Kompresiona struktura, Metod Snage gustine, Topolo ko mapiranje, Oblik-nalaz Journal of Applied Engineering Science 14(2016)1

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doi:10.5937/jaes14-10450 PRIMENA CINK-SILIKATNIH PREMAZA U TARNIM SPOJEVIMA

Nenad Fric, Univerzitet u Beogradu, Gra$evinski fakultet, Beograd Dragan Bu$evac, Univerzitet u Beogradu, Gra$evinski fakultet, Beograd Zoran Mi kovi", Univerzitet u Beogradu, Gra!evinski fakultet, Beograd Zlatko Markovi", Univerzitet u Beogradu, Gra!evinski fakultet, Beograd Jelena Dobri", Univerzitet u Beogradu, Gra!evinski fakultet, Beograd Milan Spremi", Univerzitet u Beogradu, Gra!evinski fakultet, Beograd Primenom cink-silikatnih premaza kao antikorozione za tite tarnih povr ina skra uje se vreme izgradnje konstrukcija i obezbe uje za tita od korozije. Ovakav sistem za tite ima niz prednosti u odnosu na iroko primenjivan postupak metalizacije, pre svega u smislu brzine sprovo enja, zahtevane kvalifikovanosti radne snage i cene. U ovom radu prikazani su koeficijenti trenja za razli ite sisteme antikorozione za tite tarnih spojeva, sa akcentom na cink-silikatne premaze i njihove tehni ke karakteristike i na in primene. Klju ne re i: Cink-silikatni premaz, Koeficijent trenja, Tarne povr ine, SRPS, Evrokod doi:10.5937/jaes14-10455

Broj rada: 14(2016)1, 364

UTICAJ POSLOVNE REPUTACIJE NA REZULTATE DELATNOSTI ORGANIZACIJE GRA#EVINSKE SFERE Vladimir Okrepilov, Dr avni Regionalni Centar za Standardizaciju, Metrologiju i Testiranje, St. Petersburg, Rusija Marina Gravit, Dr avni Regionalni Centar za Standardizaciju, Metrologiju i Testiranje, St. Petersburg, Rusija Ekaterina Nedviga, Dr avni Regionalni Centar za Standardizaciju, Metrologiju i Testiranje, St. Petersburg, Rusija Dudnik Oleg, Dr avni Regionalni Centar za Standardizaciju, Metrologiju i Testiranje, St. Petersburg, Rusija Razmotrena su pitanja poslovne reputacije organizacije i reputacionog rizika. Posebna pa nja posve ena je razradi nacionalnih standarda po oceni iskustva i poslovnoj reputaciji organizacije. Dati opis i osnova stvaranja standarda po oceni iskustva i poslovnoj reputaciji gra evinskih organizacija. Rasmotrena je metodika ocenjivanja poslovne reputacije, dozvoljavaju i ocenjivanje nematerijalnih aktiva gra evinskog preduze a. Metodika uklju uje u sebe pet faktora, od kojih svaki uklju uje u sebe niz podfaktora. U rezultatu ocenjivanja u skladu sa datom metodikom po standardu GOST R 56002-2014 «Ocena iskustva i poslovne reputacije gra evinskih organizacija» gra evinskoj kompaniji dodeljuje se odre eni indeks poslovne reputacije. Klju ne re i: Poslovna reputacija, Reputacioni standard, Metodika ocenjivanja, Gra evinarstvo

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doi:10.5937/jaes14-10528

SVETLO OTKRIVA ARHITEKTONSKU FORMU - ULOGA SVETLA U SAVREMENIM INTERPOLACIJAMA Sanja Paunovi! ari!, Univerzitet Crne Gore, Arhitektonski fakultet, Podgorica, Crna Gora Veljko Radulovi!, Univerzitet Crne Gore, Arhitektonski fakultet, Podgorica, Crna Gora Ema Alihod i! Ja arovi!, Univerzitet Crne Gore, Arhitektonski fakultet, Podgorica, Crna Gora Vera Murgul, Dr avni Politehni"ki Univezitet, St. Petersburg, Rusija Projektovanje fasadnog omota a u odnosu na karakteristike svetla kre e se od odgovora na prirodne elemente konteksta, preko tretmana svetla kao materije, uloge svetla u konstruisanju i transformisanju arhitekture, uloge svetla u privla enju pa nje, do komunikativne i interaktivne uloge svetla u media gradovima. Analizirano je transponovanje tradicionalnih elemenata, univerzalnog odgovara na uslove lokaliteta, transformi u i njihove formalne mogu nosti upotrebom novih tehnolo kih dostignu a. Kao takva, arhitektura mo e interpolirati i vratiti mestu i odvijanjima u prostoru. Klju ne re i: Svetlo kao materijal, Fasada, Interpolacija, Media fasade, Dnevno svetlo Broj rada: 14(2016)1, 366

doi:10.5937/jaes14-10468

POSTIZANJE RODNE RAVNOPRAVNOSTI U OBRAZOVANJU U GRA#EVINARSTVU U CRNOJ GORI Mladen Perazi!, Privredna komora Crne Gore Nevenka Pavli"i#, Privredna komora Crne Gore Milo Kne evi#, Privredna komora Crne Gore Postizanje rodne ravnopravnosti u procesu obrazovanja je dugotrajan postupak koji je rezultirao injenicom da se nivo obrazovanja ena u Crnoj Gori ve dugo izjedna ava sa nivoom obrazovanja mu karaca. Tako, jednake mogu nosti polova u zapo l!avanju bi trebalo da bude rezultat takve situacije. Me"utim, podaci pokazuju da su ene neuspe ne, koliko i mu karci, kako bi se osiguralo uspe nu karijeru. U poslednjih nekoliko godina, situacija u obrazovanju u gra"evinarstvu je promenjena na bol!e, i u tom smislu ene zauzimaju odgovaraju e pozicije u ovoj oblasti privrede. Klju ne re i: Obrazovanje, Kvalitet, Gra"evinarstvo doi:10.5937/jaes14-10217

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PROSTRANSTVO REGIONALNIH AGLOMERACIJA I REINDUSTRIJALIZACIJA Mikhail Valerievich Shubenkov, Moskovski Institut Arhitekture, Moskva Rusija Dmitriy Alksandrovich Khomyakov, Moskovski Institut Arhitekture, Moskva Rusija Dati rad posvecen je temi analize formoobrazuju eg potencijala proizvodstvenih procesa i prate ih infrastrukturnih mre a u sastavu urbanizovanih teritorija. Autori istra uju mehanizme istiskavanja proizvodnje i usluga na periferiju. Po prvi put su analizirani procesi vra anja industrije u velike gradove i savladavanje njene izolacije od gradske tkanine zajedno sa opredeljenjem njihovih teritorija kao perspektivnih objekata spoljnih investicija. Rezultati istra ivanja otkrivaju mogu nosti pove anja nivoa samoobezbe"enosti gradova, sni enja upotrebe spoljnjih resursa, pove anja njihove produktivnostu, uklju uju i i raspodelu sistema proizvodnje i upotrebe energije. Klju ne re i: Industrija, Teritorija, Aglomeracija, Mre a, Produktivnost, Infrastruktura, Personalizacija, Autonomija, Energetska efikasnost

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doi:10.5937/jaes14-10472 EKSPERIMENTALNO ISPITIVANJE KOMPOZITNIH SENDVI! PLO!A SA RAZLI!ITIM SPOLJA NIM PLO!AMA

Ana Trombeva-Gavriloska, Univerzitet Sv. Kiril i Metodij Skoplje, Arhitektonski fakultet, Skoplje, Makedonija Marijana Lazarevska, Univerzitet Sv. Kiril i Metodij Skoplje, Arhitektonski fakultet, Skoplje, Makedonija Meri Cvetkovska, Univerzitet Sv. Kiril i Metodij Skoplje, Arhitektonski fakultet, Skoplje, Makedonija U ovaj rad prezentirani su ekspeimentalni rezultati za dve serije sendvi panela sa spolja nim kompozitnim plo ama koje se razlikuju po upotrebljenoj matrici. Sendvi plo e ispitivane su prilaganjem linijskog optere enja u sredini raspona. Analize su izvedene kako bi se ocenio uticaj tipa matrice na grani ne mehani ke karakteristike sendvi panela. Uticaj tipa matrice kompozitnih spolja nih plo a je ocjenjen analizom F- ponasanja sendvi plo a, kako i F- pona anja kompozitnih plo a. Klju ne re i: Kompozitne sendvi plo e, Mehani ke karakteristike, Ekperimentalna ispitivanja Broj rada: 14(2016)1, 369

doi:10.5937/jaes14-10064

STANDARDI I NADLE NOSTI EU - TR I NE STRATEGIJE FINANSIJSKIH USLUGA U REGIONU BALKANA Nada Vignjevi" #or$evi", Dr avni Univerzitet Novi Pazar, Novi Pazar Ulazak novih lanica u Evropsku uniju, srec!no se poklopio sa ekonomskim usponom irom sveta. Industrija Investicionih ulaganja se pozicionirala u to vreme ekspanzije rasta na evropskim tr i tima i na tr i tima zemalja u razvoju. Do lo je do irenja evropskog tr i ta kapitala, kome je prethodio dug period pripreme novih lanova, u kojima su se osetili pozitivni efekti povezivanja sa zrelijim tr i tima. Stru njaci Svetske banke isti u da se razvojne politike ove svetske organizacije, reflektuju na osam novih lanova EU. Evropska unija bi trebalo da usvoji proaktivan stav u preduzimanju daljih finansijskih reformi i da pored brzog rasta bankarskog sektora stimuli e i rast u obliku nebankarskih finansijskih usluga. Rast i uloga velikih akcionara, tako"e, koincidira i zdru ena je sa ja anjem uloge institucionalnih investitora i u tom smislu, ja anti ulogu stejkholdera zajedno sa predstavnicima finansijskih institucija iz oblasti osiguranja, penzionih fondova i investicionih fondovava. Najvec!im delom tednje upravljaju, upravo, institucionalni investitori. U tede ostvaruju prednosti kod finansijskih inovacija, koje zna ajno smanjuju tro kove investicionih ulaganja i pobolj avaju kvalitet i portfolio ulaganja. Ovaj skup pojedina ne tednje je pobolj ao efikasnost risk menad menta i sa druge strane, vi estruko pove ao postizanje ekonomije obima transakcija. Tako"e, tedi e mogu da o ekuju vi i nivo prihoda za isti nivo rizika. Klju ne re i: Tr i ne strategije, Finansijske usluge, Standardi, Kompetencije, EU

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