Static Analysis Structure using E-Tabs of Braced Tube

Page 1

GRD Journals- Global Research and Development Journal for Engineering | Volume 5 | Issue 11 | October 2020 ISSN- 2455-5703

Static Analysis Structure using E-Tabs of Braced Tube Sanjith J Assistant Professor Department of Civil Engineering Adhichunchanagiri Institute of Technology

Jayachandra Assistant Professor Department of Civil Engineering REVA University, Bangalore, Karnataka

Chethan G Assistant Professor Department of Civil Engineering Adhichunchanagiri Institute of Technology

Kiran B M Associate Professor Department of Civil Engineering Adhichunchanagiri Institute of Technology

Abstract In tall buildings, tubular structures have become a popular feature over the past few years. For all tall buildings, tubing in tube systems is especially tubes at the corners; the whole building behaves like a massive tube. Between the inner and outer tubes, lateral loads are exchanged. Different models were developed in the E-TABS V15 programme to research the seismic performance of tubes in tube structures by varying the position of the inner tubes. The structures are studied using a continuum method in which the horizontal slabs and beams connecting vertical components are considered to have equal distributed stiffness properties as a continuous connecting medium. To have a comparative analysis on the model, the equivalent static is evaluated Suitable. A tube contains a peripheral framed tube and a central tube interconnected by floor slabs in a tube framework. With smaller. Keywords- Tube-in-Tube, Static Analysis, Lateral Loads, E-TABS 2015

I. INTRODUCTION Advances in structural structures, increase in building height and slenderness, use of high-strength materials, decrease in building weight, etc. have now allowed lateral loads, such as wind and earthquake, to be taken into account in the design process. In design considerations, lateral forces arising from wind and seismic activities are now dominant. The lateral movement of such structures must be strictly controlled, not only for the comfort and protection of occupants, but also for the control of secondary structural effects. There are currently several structural structures that can be used to improve the lateral resistance in tall buildings, such as rigid frame, braced frame, shear-walled frame, frame-tube, braced-tube, bundled-tube and Outrigger structures. Tubular structures have been used successfully and in tall buildings are becoming a common feature. The framed tube, central tube, tube-in-tube and bundled tube are fundamental types of tubular structures. The layout of a tube-in - tube consists of a framed peripheral tube and a central tube interconnected by floor slabs. For any one of these Various simplified models have been developed for vertical components to evaluate the behaviour of the system under lateral loads. Over the past decades, several researchers have developed approximate techniques for a single tube and multi-tube device. A tube-in - tube structure’s exterior and interior columns is mounted so closely together that they not only appear to be rigid, but they also serve as a solid surface. The whole building works as a massive hollow tube with a hollow tube in the centre of it is a smaller tunnel. Between the inner and outer tubes, lateral loads are exchanged. Tubular structures have been used successfully and in tall buildings are becoming a common feature. A tube-in - tube structure’s exterior and interior columns is mounted so closely together that they not only appear to be rigid, but they also serve as a solid surface. The whole building works as a massive hollow tube with a hollow tube In the centre of it is a smaller tunnel. Between the inner and outer tubes, lateral loads are exchanged. Tubular structures have been used successfully and in tall buildings are becoming a common feature. Basic forms of tubular systems are:– Framed Tube – Braced Tube – Bundled Tube – Tube-in-Tube The theory of the tube system is based on the idea that a building can be built by constructing it as a hollow cantilever perpendicular to the ground to withstand lateral loads. The perimeter of the outside consists of closely spaced columns in the simplest embodiment of the tube, which are connected by moment ties with deep spandrel beams. This arrangement of columns and beams forms a rigid structure along the exterior of the building that contributes to a thick and solid structural wall.

All rights reserved by www.grdjournals.com

38


Static Analysis Structure using E-Tabs of Braced Tube (GRDJE/ Volume 5 / Issue 11 / 005)

II. LITERATURE REVIEW Peter C. Chang(1) (1985) He analyzed Tube-in-tube structures using a continuum approach. Flexural deformation, shear deformation, and shear-lag effects are studied. The beams are forced to have equal lateral deflections, and the amount of load carried by each beam is a function of its relative stiffness The analyses are performed using the Minimum Potential Energy principle, and the results are compared with results of finite element analyses. An effective method was proposed for evaluating the global deflection behaviour of a tube-in - tube system. The lateral deflection compatibility of the two tubes is applied, reducing the two sets of differential equations to a set of 10 first-order differential equations. J. Connor, J, and C. C. Pouangare(2) (1991) suggested a rather basic model for the study and design of framed-tube structures subjected to lateral loads. As a set of stringers and shear tables, the structure is modeled. To achieve the desired outcomes, the analytical expressions for the stresses and displacements are finished. The model can be used directly for the study of structures along the height of the structure that integrate various materials and distinct properties. M. R. Jahanshahi, R. Rahgozar, M. Malekinejad (3)(2012) Parametric functions for static study of tall buildings with a combined tube in-tube and outrigger-belt truss system subjected to three different clustered load cases at the top of the structure, distributed loads uniformly and triangularly around the height of the structure. The formulas suggested here were validated by contrasting them with the results of the machine static analysis obtained from three-dimensional It has been shown that results computed by the energy method correlate well with those obtained by means of E-TABS analysis. Kang-Kun Lee, Yee-Chaye Loo, Hong Guan(4) (2001) Proposed For the approximate study of framed-tube systems with multiple internal tubes, a basic mathematical model is proposed. Comparisons with the two current simplified methods and a 3D frame analysis programme check the precision, simplicity, and reliability of the proposed system. Often accounted for in the study is the extra lateral stiffness due to the contact of the tube-tube. It is found that additional bending stresses have a major impact on the phenomenon of shear-lag. The proposed method provides equally accurate results in predicting the deflection response and the column axial stress distributions in comparison with the 3D frame analysis software, the only other methodology available for the tubes-in-tube system.

III. SCOPE OF WORK The main objective of this paper is to investigate the performance of a Braced Tube structure with different positioning of the internal tube. The study of static analysis part has been done by developing model in ETABS-2015. The displacement parameters at each floor level for Equivalent static, are plotted and a comparative study is conducted which is expected to present the effect of torsion and pounding gap of adjacent building. A 15 storied building are modeled with story height 4m with Distance of 8.5m c-c. The total base area of the building is 51 x 51 m2. The building consists of rectangular composite columns with dimensions 1700mmx1300mm and another column size of 1400mmx1000mm.Composite beams with dimension 1000mm x800mm and another beam size of 900mmx700mm.The floor slabs are of 200mm thick and the tube side Bracings of ISWB550. Grade of concrete used is M30&M45.The modulus of elasticity (E) and the shear modulus (G) are taken as 2.73x 107 KN/m2 and 1.14 x107KN/m2. The base plan and various positioning are shown in Fig.1,2&3 Respectively. The gravity loads include beam, column, slab, wall and other permanent members. The programme itself automatically considers the self-weight of the beams , columns (frame members) and the slab (area element). Wall loads are independently measured and applied to beams as uniformly distributed loads. As per IS 1893 (Part 1) 2002, live loads are allocated as a uniform area load on the slab portion. Live load is taken as 4 KN/ m2 on the roof and as 5 KN/ m2 on the floor.

Fig. 1: Base Plan of the model

Fig. 2: 3-D View of the Model

All rights reserved by www.grdjournals.com

39


Static Analysis Structure using E-Tabs of Braced Tube (GRDJE/ Volume 5 / Issue 11 / 005)

Table1: Story Displacement with Respect to Story Height in Static Analysis Story 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Displacement(mm) Load Combination Ux (mm) Comb1 4.3 Comb1 3.9 Comb1 0.9 Comb1 -0.9 Comb1 0.1 Comb1 -0.1 Comb1 0.1 Comb1 0.1 Comb1 0.1 Comb1 0.1 Comb1 0.02205 Comb1 0.01058 Comb1 0.02853 Comb1 0.0013862 Comb1 0.0019 Comb1 0

Uy(mm) 5.5 4.9 1.9 0.7 0.7 0.6 0.4 0.2 0.1 0.0178 0.02253 0.01829 0.01062 0.1 0.00581 0

IV. ANALYSIS The analyses carried out are 1) Equivalent Static Analysis 2) Dynamic Analysis A. Equivalent Static Analysis The proceedings are carried out in compliance with IS 1893 (Part 1) 2002. For the building, the design base shear is first computed and then distributed along the overall height. Thus, the lateral force is distributed to individual lateral load resisting elements at each floor level. Floor finish and wall load will be considered for the review because of the live load as well as dead load. After that, by assigning those loads to the model, the model was analysed.

V. RESULTS & DISCUSSION – – –

Table1 Illustrate the Compassion of Story Displacement with Respect To story height done in Static Analysis. Structural Modelling of framed tube structure is done using E-TABS, to obtain the consistent results, floor Height is kept constant for all Story. Fig4.Illustrate the Displacement Graph, By Consider the Height in meter along x-axis and Displacement along Y-axis.

Fig. 3: Graph Showing the Results of Displacement

Here Blue Colure indicates the X-axis and Red Colure indicates the Y-axis. Hence it indicates that Displacement is maximum at 15th story. Later on it starts to reduce. All rights reserved by www.grdjournals.com

40


Static Analysis Structure using E-Tabs of Braced Tube (GRDJE/ Volume 5 / Issue 11 / 005)

Fig. 4: Showing the Bending Movement Reaction of All Story

Fig. 5: Shows the Bending Moment Reaction

This is the Plan of the 15th Story Here Sagging Moment Ranges from 502.1713kn-m, to 307.623kn-m.As well as Hogging Moment Ranges From-291.0848kN-m to-782.6957kN-m.

Fig. 6: Shows the Shear Force Reaction All Story

VI. CONCLUSION Analysis is carried out for the given model. – From the above study we can observe that static analysis is done for the tube structure, and it will give the maximum displacement at 15th story. – Compared other structure tube structure will perform better for lateral loads & reduces the displacement also. All rights reserved by www.grdjournals.com

41


Static Analysis Structure using E-Tabs of Braced Tube (GRDJE/ Volume 5 / Issue 11 / 005)

– – – – –

In the story 15 we get maximum displacement, it is that 4.3mm along X-axis and Along 5.5mm Along Y-axis. Displacement starts to reduce from Top story to Bottom story. Displacement from 1st story to 5th story will be remains same along X-axis as well Y-axis, it is that 0.0019 mm to 0.02205mm.And Bottom story it will be 0. Similarly From 6th Story to 13th Story Displacement in X-axis will be 0.1mm to 0.9mm & Displacement Along Y-axis will be 0.012 to 1.9mm. In case of 14th and 15th Story Displacement will be maximum it is that Along X–axis it will be 3.9mm and 4.3mm respectively and along Y-axis it will be 4.9mm and 5.5mm respectively.

REFERENCES Peter C. Chang,” Analytical modeling of tube-in-tube structure “ASCE Journal of Structural Engineering, Vol. I l l , No. 6, June J. J, Connor and C. C. Pouangare “Simple model for design of framed-tube “ ASCE Journal of Structural Engineering, Vol. 117, No. 12,December, 1991 M. R. Jahanshahi, R. Rahgozar, M. Malekinejad “A simple approach to static analysis of tall buildings with a combined tube-in tube and outrigger-belt truss system subjected to lateral loading “ IjeTransactionsA: Basics Vol. 25, No. 3, July 2012 [4] Kang-Kun Lee, Yee-Chaye Loo, Hong Guan “Simple [5] Analysis of Framed-Tube Structures with Multiple Internal Tubes” Journal of Structural Engineering, Vol. 127, No. 4, April, 2001. [6] Myoungsu Shin1, Thomas H.-K. Kang ,James M. LaFave and Jacob S. Grossman “Design and behavior of a reinforced concrete high-rise tube building with belt walls” Struct. Design Tall Spec. Build. 2010 [7] Mir M. Ali “Performance characteristic of tall framed tube buildings in seismic zones” Eleventh World Conference Of Earthquake Engg 1996 [8] Wang Hi Bo, ShenPu Sheng “Nonlinear seismic response analysis of reinforced concrete tube in tube structures” J Cent South UnivTechnolVol 12 October 2005woln Pu-Shengj. CENT. SOUTH UNIV.TECHNOLOGY. [9] DhanapalgoudPatil and Naveena M P, “Dynamic Analysis of Steel Tube Structure with Bracing System”, International Journal of Research in Engineering and Technology Eissn:2319-1163,Pissn:2321-7308,Vol.04.Issue :08 August-2015 . [10] Basavanagouda A Patil and Kavitha S, “Dynamic Analysis of Tall Tubular Steel Structures for Different Configuration,” International Engineering Research, ISSN:Vol.4.Issue.4.2016I(July-August). [11] Jignesha Patel ,Roshni J John, “Siesmic Analysis of Frame Tube Structure”, International Journal of Scientific &Engineering Research, Vol.6, Issue 12. [1] [2] [3]

All rights reserved by www.grdjournals.com

42


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.