Trends in Machine Design in vol 3 issue 3 by STM Journals

ISO: 9001Certified

ISSN 2455-3352 (Online)

STM Journals Empowering knowledge

Trends in

Machine Design

Free Online Registration

Septemberâ&#x20AC;&#x2019;December 2016 22

Energy /

/ Instrumentation /Science

GLOBAL READERSHIP STATISTICS

conducted

Over 500 Indian and International Subscribers. 30,000 Top Researchers, Scientists, Authors and Editors All Over the World Associated. Editorial/ Reviewer Board Members : 1000+. 1,00,000+ Visitors to STM Website From 140+ Countries Quarterly. 10,000 + Downloads from STM Website.

STM Journals invites the papers from the National Conferences, International Conferences, Seminars conducted by Colleges, Universities, Research Organizations etc. for Conference Proceedings and Special Issue. xSpecial Issues come in Online and Print versions. xSTM Journals offers schemes to publish such issues on payment and gratis (online) basis as well.

To g e t m o r e i n f o r m a t i o n : stmconferences.com

STM JOURNALS Scientific

Technical

Medical

www.stmjournals.com

(TMD)

STM Journals STM Journals, a strong initiative by Consortium E-Learning Network Private Ltd. (established 2006), was launched in the year 2010 under the support and guidance by our esteemed Editorial and Advisory Board Members from renowned institutes. Objectives: 

Promotion of Scientific, Technical and Medical research.



Publication of Original Research/Review, Short Articles and Case Studies through Peer Review process.



Publishing Special Issues on Conferences.



Preparing online platform for print journals.



Empowering the libraries with online and print Journals in Scientific, Technical and Medical domains.



Publishing and distribution of books on various subjects in the category of Nanotechnology, Scientific and Technical Writing, and Environment, Health and Safety.

Salient Features: 

A bouquet of 100+ Journals that fall under Science, Technical and Medical domains.



Employs Open Journals System (OJS)—a journal management and publishing system.



The first and one of the fastest growing publication website in India as well as in abroad for its quality and coverage.



Rapid online submission and publication of papers, soon after their formal acceptance/finalization.



Facilitates linking with the other authors or professionals.



Worldwide circulation and visibility.

Trends in Machine Design ISSN: 2455-3352(online)

Focus and Scope Covers 

Kinematics of Machines



CAD/CAM/CAE technology



Fatigue and Their Failure



Mechatronic design



Machine manufacturing processes



Machine learning algorithms



Brakes, clutch, GEARS and SPRINGS design

Trends in Machine Design is published (frequency: three times a year) in India by STM Journals (division of Consortium e-Learning Network Private Ltd.) The views expressed in the articles do not necessarily reflect of the Publisher. The publisher does not endorse the quality or value of the advertised/sponsored products described therein. Please consult full prescribing information before issuing a prescription for any products mentioned in this publication. No part of this publication may be reproduced, stored in retrieval system or transmitted in any from without written permission of the publisher. To cite any of the material contained in this Journal, in English or translation, please use the full English reference at the beginning of each article. To reuse any of the material, please contact STM Journals (info@stmjournals.com)

STM Journals (division of Consortium e-Learning Network Private Ltd. ) having its Marketing office located at Office No. 4, First Floor, CSC pocket E Market, Mayur Vihar Phase II, New Delhi-110091, India is the Publisher of Journal. Statements and opinions expressed in the Journal reflect the views of the author(s) and are not the opinion of STM Journals unless so stated. Subscription Information and Order:  National Subscription: Print - Rs 3750/- per Journal ( includes 3 print issues), Single Issue copy purchase: Rs 1500. Online - Rs 3750/- per Journal inclusive Service Tax ( includes 3 online issues), Single Issue purchase: Rs 1500

inclusive Service Tax Print + Online - Rs 5000/- per Journal inclusive Service Tax ( includes 3 print & online issues).  International Subscription:  Online Only- $199, Print Only-$299 (includes 3 print issues)  Online + Print-$399 (includes 3 print issues + online access of published back volumes )

To purchase print compilation of back issues please send your query at info@stmjournals.com Subscription must be prepaid. Rates outside of India includes delivery. Prices subject to change without notice. Mode of Payment: At par cheque, Demand draft, and RTGS (payment to be made in favor of Consortium E-Learning Network. Pvt. ltd., payable at Delhi/New Delhi. Online Access Policy A). For Authors: In order to provide maximum citation and wide publicity to the authors work, STM Journals also have Open Access Policy, authors who would like to get their work open access can opt for Optional Open Access publication at nominal cost as follows India, SARC and African Countries: INR 2500 or 100 USD including single hard copy of Author's Journal. Other Countries: USD 200 including single hard copy of Author's Journal. B). For Subscribers:  Online access will be activated within 72 hours of receipt of the payment (working days), subject to receipt of

correct information on user details/Static IP address of the subscriber.  The access will be blocked:  If the user requests for the same and furnishes valid reasons for blocking.  Due to technical issue.  Misuse of the access rights as per the access policy.

Advertising and Commercial Reprint Inquiries: STM Journals with wide circulation and visibility offer an excellent media for showcasing/promotion of your products/services and the events-namely, Conferences, Symposia/Seminars etc. These journals have very high potential to deliver the message across the targeted audience regularly with each published issue. The advertisements on bulk subscriptions, gift subscriptions or reprint purchases for distribution etc. are also very welcome. Lost Issue Claims: Please note the following when applying for lost or missing issues:  Claims for print copies lost will be honored only after 45 days of the dispatch date and before publication of the

next issue as per the frequency.  Tracking id for the speed post will be provided to all our subscribers and the claims for the missing Journals will

be entertained only with the proofs which will be verified at both the ends.  Claims filed due to insufficient (or no notice) of change of address will not be honored.  Change of Address of Dispatch should be intimated to STM Journals at least 2 months prior to the dispatch

schedule as per the frequency by mentioning subscriber id and the subscription id.  Refund requests will not be entertained.

Legal Disputes All the legal disputes are subjected to Delhi Jurisdiction only. If you have any questions, please contact the Publication Management Team: info@stmjournals.com; Tel : +91 0120-4781211.

PUBLICATION MANAGEMENT TEAM Chairman Mr. Puneet Mehrotra Director

Group Managing Editor Dr. Archana Mehrotra Managing Director CELNET, Delhi, India

Internal Members Gargi Asha Jha Manager (Publications)

Quaisher J Hossain Senior Editor Senior Associate Editors

Himani Pandey Isha Chandra

Meenakshi Tripathi Shivani Sharma

Associate Editors Shambhavi Mishra

Sugandha Mishra

External Members Bimlesh Lochab Assistant Professor Department of Chemistry School of Natural Sciences, Shiv Nadar University Gautam Buddha Nagar, Uttar Pradesh, India

Dr. Rajiv Prakash Professor and Coordinator School of Materials Science and Technology Indian Institute of Technology (BHU), Varanasi Uttar Pradesh, India

Prof. S. Ramaprabhu Alternative Energy and Nanotechnology Technology Laboratory, Department of Physics Indian Institute of Technology, Chennai Tamil Nadu, India

Dr. Khaiser Nikam Professor, Library and Information Science Department of Library and Information Science University of Mysore Mysore, India

Dr. Yog Raj Sood Dean (Planning and Development) Professor, Department of Electrical Engineering National Institute of Technology, Hamirpur Himachal Pradesh, India

Prof. Chris Cannings Professor, School of Mathematics and Statistics University of Sheffield, Sheffield United Kingdom

Dr. Rakesh Kumar Assistant Professor Department of Applied Chemistry BIT Mesra, Patna, Bihar, India

Dr. Durgadas Naik Associate Professor (Microbiology) Management and Science University, University Drive, Seksyen13 Selangor, Malaysia

Prof. José María Luna Ariza Department of Computer Sciences and Numerical Analysis Campus of Rabanales University of Córdoba, Spain

Dr. D. K. Vijaykumar MS, MCh (Surgical Oncology), Professor and Head Department of Surgical Oncology Amrita Institute of Medical Sciences and Research Centre Ponekkara, Cochin, Kerala, India

STM JOURNALS

ADVISORY BOARD Dr. Baldev Raj

Dr. Hardev Singh Virk

Director, National Institute of Advanced Studies Indian Institute of Science campus Bangalore Karnataka, India Former Director Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, India

Visiting Professor, Department of Physics University of SGGS World University Fatehgarh Sahib, Punjab, India Former Director Research DAV Institute of Engineering and Technology Jallandhar, India

Dr. Bankim Chandra Ray Professor and Ex-Head of the Department Department of Metallurgical and Materials Engineering National Institute of Technology, Rourkela Odisha, India

Prof. D. N. Rao Professor and Head Department of Biochemistry All India Institute of Medical Sciences New Delhi, India

Dr. Pankaj Poddar

Dr. Nandini Chatterjee Singh

Senior Scientist Physical and Materials Chemistry Division, National Chemical Laboratory Pune, Maharastra India

Additional Professor National Brain Research Centre Manesar, Gurgaon Haryana, India

Prof. Priyavrat Thareja

Dr. Ashish Runthala

Director Principal Rayat Institute of Engineering and Information Technology Punjab, India

Lecturer, Biological Sciences Group Birla Institute of Technology and Science Pilani, Rajasthan, India

Dr. Shrikant Balkisan Dhoot

Prof. Yuwaraj Marotrao Ghugal

Senior Research Scientist, Reliance Industries Limited, Mumbai, India Former Head (Research and Development) Nurture Earth R&D Pvt Ltd., MIT Campus Beed Bypass Road, Aurangabad Maharashtra, India

Professor and Head Department of Applied Mechanics Government College of Engineering Vidyanagar, Karad Maharashtra, India

STM JOURNALS

ADVISORY BOARD Dr. Baskar Kaliyamoorthy

Dr. Shankargouda Patil

Associate Professor Department of Civil Engineering National Institute of Technology, Trichy Tiruchirappalli, Tamil Nadu, India

Assistant Professor Department of Oral Pathology KLE Society's Institute of Dental Sciences Bangalore, Karnataka, India

Prof. Subash Chandra Mishra

Prof. Sundara Ramaprabhu

Professor Department of Metallurgical and Materials Engineering National Institute of Technology, Rourkela Odisha, India

Professor Department of Physics Indian Institute of Technology Madras Chennai, Tamil Nadu India

Dr. Rakesh Kumar Assistant Professor Department of Applied Chemistry Birla Institute of Technology Patna, Bihar, India

Editorial Board

Arindam Majumder

Dilip Datta

Assistant Professor,National Institute of Technology, Agartala.

Head,Mechanical Engineering Tezpur University, Assam.

Dinesh Kumar Assistant Professor, Department of Mechanical Engineering, Malaviya National Institute of Technology, Jaipur.

Hemanta Kumar Assistant Professor, National Institute of Technology, Suratkhal India.

LA Kumaraswamidhas Associate Professor, Department of Mechanical Engineering and Mining Machinery Engineering, Indian School of Mines Dhanbad, India.

Rajeev Jain, Head Mechanical Engineering Department, Kalaniketan Polytechnic College Jabalpur India.

Sanjivi Arul Associate Professor, Mechanical Engineering, Amrita School of Engineering, Coimbatore.

Rakesh Kumar Maurya Assistant Professor, School of Mechanical, Materials & Energy Engineering Indian Institute of Technology ,Ropar, India.

K Priya Ajit, Assistant Professor Department Of Mechanical Engineering & Mining Machinery Engineering Indian School Of Mines, Dhanbad, India.

Manju Singh Principal Scientist Central Mechanical Engineering Research Institute Durgapur, India.

S K Kakoty Professor Mechanical Engineering, Indian Institute of Technology, Guahati.

Shubhankar Bhowmick Assistant Professor, Mechanical Engineering, National Institute of Technology, Raipur, India.

Editorial Board

Prof. Rakesh Sehgal

Dr. Navin Karanth P

Mechanical Engineering Department, National Institute of Technology, Hamirpur, HP.

Asst. Professor, Dept. of Mechanical Engineering, NITK Surathkal, Karnataka.

Dr. Raghunandan Bhat Professor, Dept. of Mechatronics Engineering, MIT, Manipal.

Dr. Srikanth Bontha Asst. Professor, Dept. of Mechanical Engineering, NITK Surathkal, Karnataka.

Ramesh S Asst. Professor, Dept. of Mechanical Engineering, R V College of Engineering, Bangalore.

Sujan Chakraborty ME Department, R.V. College of Engineering, Bangalore

Dr. Vijay Desai Professor, Dept. of Mechanical Engineering, NITK Surathkal, Karnataka

M. K. Pradhan Assistant Professor, Department of Mechanical Engineering, Maulana Azad National Institute of Technology, Bhopal.

Dr. Siddaraju C Department of Mechanical Engineering, M. S. Ramaiah Institute of Technology, Bangalore.

Chetan Patel Mechanical Engineering, RK University, Kasturbadham Rajkot, Gujarat.

Director's Desk

STM JOURNALS

It is my privilege to present the print version of the [Volume 3, Issue 3] of our Journal of Trends in Machine Design(TMD), 2016. The intension of TMD Journal is to create an atmosphere that stimulates vision, research and growth in the area of Mechanical Engineering. Timely publication, honest communication, comprehensive editing and trust with authors and readers have been the hallmark of our journals. STM Journals provide a platform for scholarly research articles to be published in journals of international standards. STM journals strive to publish quality paper in record time, making it a leader in service and business offerings. The aim and scope of STM Journals is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high level learning, teaching and research in all the Scientific, Technical and Medical domains. Finally, I express my sincere gratitude to our Editorial/ Reviewer board, Authors and publication team for their continued support and invaluable contributions and suggestions in the form of authoring write ups/reviewing and providing constructive comments for the advancement of the journals. With regards to their due continuous support and co-operation, we have been able to publish quality Research/Reviews findings for our customers base. I hope you will enjoy reading this issue and we welcome your feedback on any aspect of the Journal.

Dr. Archana Mehrotra Managing Director STM Journals

Editorial

Design To develop state-of-the-art and worthwhile engineered products, it is very critical to address the user needs and preferences which is intrinsically challenging. It is also necessary to assimilate user likings with technical and costeffective necessities throughout the engineering design process. Since the past few years, there was a substantial progression in user-concentrated design research that presents ideologies from altered fields like social science, cognitive science, economics and market research; there is still a deficiency of incorporation of these procedures, either quantitative or qualitative, for straight backup engineering design judgments. Hence it is necessary to improve interdisciplinary design tactics to discourse â&#x20AC;&#x153;interfaceâ&#x20AC;? matters amid various fields and engineering design, considering environmental impact assessments, social behavior, usage context, market demand and other issues. The worthiness of a product/service will be influenced by; on to what degree the product/service gratifies the customer desires. In adding to categorical customer desires, concealed customer wishes are predominantly precarious to product modernization and realization. Common methods to customer requirements elicitation encompass steps such as: 1. Raw data collection from customers, 2. Assigning the collected data into customer desires, 3. Consolidating the customer desires into a pecking order of primary, secondary and tertiary wishes, 4. Listing the customer desires with qualified prominence, and 5. Replicating on the outcomes and process. The difficulties in latent customer needs elicitation are: 1. Multichannel data collection. 2. Linguistic investigation of customer desires. 3. Ignorance of latent customer desires. Consumers play a dynamic role in the succeeding generation product development. The chief users help the designers to determine appropriate product feature likings beforehand the general customer base desires. The prevailing design procedures which are used to mine the chief user likings are typically constrained by heterogeneity, geographic, temporal and size limitations. To moderate such tasks, a fixed number of mathematical prototypes that mine social media set-ups for chief consumers, and the product landscapes, that they prompt connecting to the exact products can be developed. The important stage in the design procedure is accepting the consumer desires which would lead to the success of the product. For various trademarked merchandises, the companies do not achieve direct consumer studies but depend on the market inclinations that product creators and marketing divisions have and the general knowledge of the target customer. Consumer likings generally account for the appearance and functions of the product, and feel to interact with the trademark and familiarity for consumers. Design of products is typically dispersed over numerous groups of specialists, who occasionally conduct their specific distinct consumer studies and reviews. The design groups comprise specialists from diverse disciplines with an altered information and understanding of the product, which have different interpretations of what customers need and wish. As the cost, performance and manufacturing feasibility of the product is important, so does the appearance. Hence both traits should be well thought out during the design process. Generally, the consumers will not be able to spell out their needs correctly. Even if they are successful, it would be in nontechnical words. Product designers, marketing experts and engineering experts act as substitutions for the consumers in the absence of market studies, by assuming what the consumer needs. After inserting these assumptions in the product specification, the document is handed over to the manufacturing cell. Typically, the final product which is manufactured may feel and look dissimilar from what was originally envisioned due to engineering fluctuations during the design procedure. Finally, the product manufactured may vary from those formerly wished-for by the product designers.

Editorial The challenges faced by the company's manufacturing and marketing trademarked goods: 1. A consistent style should be maintained across the entire product offering; 2. The emotional responses and perceptions of the consumers which are subjective and semantically unclear in their words should be understood properly. 3. A constant communication about the trademark values across the range of different brand products should be conveyed to the consumers; 4. To ensure that the trademark values and the anticipated user observations and sentiments are not battered by anticipated and unintentional engineering changes elicited by technical restraints or cost. It is interesting to note that the user inclinations and needs in design of trademarked product face numerous negotiation layers like, the design group and consumers can be addressed by additional user-focused design approaches, and the negotiation layer inside the multidisciplinary design team necessitates appropriate support for the communication of subjective and often ambiguous concepts. The products with continuous improvement in design will meet the requirement of the customers which will result in purchase of the product of his desire. Initially, the design groups will generate many design alternatives and then select one from those alternatives for further development. Feedback will be obtained from the consumers and other stakeholders on conditional design ideas by provoking a design direction. This feedback will be integrated into the future design direction by the design team. To draw financial investment, the phenomenon of tracking down feedback on conditional design representations has become more dominant through the rise of online crowdfunding sites that present consumers with preproduction designs. To authenticate business ideas with probable consumers, entrepreneurs have incorporated minimum viable product designs with low-cost and quick prototypes. Since the forecast of forthcoming demand of a product, as a function of engineering design traits and target market picture is important, the customer choice modelling is gaining increasing thoughtfulness in engineering design. A wide range of design interests such as design under market competition, platform-based product family design, social context and usage based design, hierarchical systems design, multilevel and multidisciplinary design, robust design, and consider-then-choose model to design optimization, are a few recent efforts considered towards incorporating customer preferences into engineering design. Design of products in this line is the need of the hour and would felicitate the customers.

Raghunandana Department of Mechatronics Engineering Manipal Institute of Technology (A Constituent Institute of Manipal University) Manipal, Karnataka, India

Trends in Machine Design

Contents

1. Influence of Internal and External Dampings on Shaft Whirl Speeds Ravindra Gardas, Bangarubabu Popuri

2. Six Sigma DMAIC Approach for Increasing Effectiveness of Heat Exchanger Akash A Shukla, Dhaval B Patel

3. Finite Element Analysis of Tool Wear Rate in Electrical Discharge Machining and Comparison with Experimental Results C.R. Sanghani, G.D. Acharya, K. D. Kothari

4. An Experimental Study of Wear and Frictional Behaviour of Different Metal Pairs under Different Normal Loads Deependra Singh Patel, Ashesh Tiwari

5. Stress Analysis of Variable Thickness FGM Rotating Disks by Element based Material Gradation under Thermomechanical Loading Amit Kumar Thawait, Lakshman Sondhi, Shubhankar Bhowmick, Shubhashis Sanyal

6. Failure Analysis of Bearing: A Review Pranav P. Bagdiya, Ashok J. Keche

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

Influence of Internal and External Dampings on Shaft Whirl Speeds Ravindra Gardas1,*, Bangarubabu Popuri2 1

Rotating Machines Division, General Electric, Hyderabad, Telangana, India Department of Mechanical Engineering, National Institute of Technology, Warangal, Telangana, India

Abstract A mathematical model is developed for the estimation of rotor forward and backward whirl speeds by considering the stationary and rotational dampings. Stationary damping includes external viscous damping in the bearings and rotational damping includes internal viscous and hysteretic damping in the shaft material. The rotors in gas turbines and steam turbines commonly used in military and commercial rotating machines operate at high speeds. These rotors are provided with a set of holes in the shaft to send the coolant to cool the turbine blades. The estimation of the rotor whirl speeds with the above conditions is very difficult. The developed mathematical model predicts the whirl speeds by considering all the above conditions. As the rotor speed increases, the difference between forward whirl and backward whirl increases due to the gyroscopic effect. The study has been done to understand the percentage change in the ratio of forward whirl to backward whirl speed for normal rotor and rotor with above conditions. The whirl speed prediction is done with the combinations of external damping, internal viscous damping and internal hysteretic damping. The more we understand these effects, the more likely we are to make accurate rotating machine diagnoses and to develop appropriate plans for knowledge based maintenance. Keywords: Whirl speed, rotor, external damping, internal viscous damping and internal hysteretic damping

INTRODUCTION High speed machinery is used in a wide variety of applications, ranging from turbomachines in power generation to industrial machine tools. Uncontrolled and undesired vibrations in the rotating systems can lead to catastrophic failures meaning extra cost due to downtime and repair with human and property loss. The rotors in many commercial and military rotating machines operate above the critical speeds. These rotors are highly unstable at high speed. The primary destabilizing mechanism for these high speed rotors is the presence of internal damping. The internal damping may be a linear viscous and/or hysteretic in nature.

by Rankine in 1869 who performed the first analysis of a spinning shaft and attempted to establish accurate method for the estimation of whirl speeds of complex systems is explained by Downham [1]. The rotors could be operated safely beyond their first critical speeds with proper rotor balancing, that the trend in rotor dynamics design changed only after Jeffcottâ&#x20AC;&#x2122;s analysis. The first researchers to identify internal hysteretic damping in rotating machines and the internal friction which is one of the main causes of oil whipping were concluded [2]. Ehrich made the mathematical model of internal friction, which states that the internal friction stresses act in a direction perpendicular to the shaft deflection plane and

The focus of the proposed paper is on the consideration of different types of internal damping and external damping effect on the rotor critical speed and whirl speeds viz. backward whirls and forward whirls. The fundamental work in this field was pioneered

Page 1

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

Six Sigma DMAIC Approach for Increasing Effectiveness of Heat Exchanger Akash A. Shukla*, Dhaval B. Patel Department of Mechanical Engineering, Vadodara Institute of Engineering, Vadodara, Gujarat, India Abstract In a small sized furnace manufacturing company, heat exchanger is a fundamental segment. The productivity of the furnace relies on upon the proficiency and adequacy of the heat exchanger. This research uncovers the experimental execution of Six Sigma DMAIC (DefineMeasure-Analyze-Improve-Control) stages to enhance the adequacy of shell and tube heat exchanger and along these lines enhance the quality and productivity of the furnace. The basic goal is to enhance the nature of the furnace through DMAIC stages. In this case study, the define phase assesses the furnace performance, through distinguishing and lessening different multiple operational energy losses to enhance the general proficiency. In measure stage, the present effectiveness of the heat exchange rate for the heat exchanger was measured and found as 0.61. In analysis stage, there as on for the lessening of effectiveness was distinguished as less heat exchange area through cause and effect diagram. In improve stage; the existing design was modified through various alternative solutions such as factors that identify the performance of heat exchanger by conducting brain storming sessions. In this stage, the solution was identified with the introduction of circular fins over the bare tubes to improve the effectiveness in the shell and tube heat exchanger. Therefore, the effectiveness has been raised from 0.61 to 0.664. In control stage, the control techniques were prescribed to manage the upgrades in shell and tube heat exchanger. Keywords: Six Sigma, DMAIC, CTQ, quality, effectiveness, furnace, shell, tube heat exchanger

INTRODUCTION In the modern era of business practice, furnace plays an authoritative role in metal mining, metal forming and heat treatment process. The furnace products producers uphold overall competitiveness through strategic energy management by using energy efficient technologies. The execution of the furnace endeavors to upgrade the quality by considering effectiveness and execution of the furnace together. Among the different techniques accessible to enhance the furnace execution, an efficient approach ought to be utilized for accomplishing stimulus change at a moderate cost. In engineering field, the many-sided quality diminishment of the functional unit can be accomplished through either breakdown of the framework or process. The furnace has some basic performance influential components namely heat exchanger, nozzle, burner and control valve. The performance of individual components can be evaluated and integrated to embark the total performance of the furnace. The strict investigation was taken over to identify and eliminate the vital parameters that affect the

efficiency of the furnace through a systematic approach namely Six Sigma DMAIC (Define, Measure, Analyze, Improve, and Control) phases. Six Sigma is a quality management tool introduced by Bill Smith of Motorola in 1980 [1]. It is said to be fierce approach that directly hits imperative woes faced in customer end, by reducing the variation to achieve 3.4 defects per million opportunities (DPMO) that subsequently enhance the quality, market share of the manufacturing organization. The variations are controlled by using a hierarchical approach of Six Sigma DMAIC, which have been derived from Demingâ&#x20AC;&#x2122;s improvement cycle namely PDCA (Plan-Do-Check-Act). This case study performs examinations on enhancing current execution of heat exchanger that enhances the general effectiveness of the furnace by utilizing the Six Sigma DMAIC approach. In

Page 12

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

Finite Element Analysis of Tool Wear Rate in Electrical Discharge Machining and Comparison with Experimental Results C.R. Sanghani1,*, G.D. Acharya2, K.D. Kothari3 1,3

Department of Mechanical Engineering, School of Engineering, R. K. University, Rajkot, Gujarat, India 2 Department of Mechanical Engineering, Atmiya Institute of Technology and Science, Rajkot, Gujarat, India

Abstract Electrical discharge machining (EDM) is one of the precise non-traditional machining processes in which desired shape is obtained in workpiece using electrical sparks. In EDM, material removal from workpiece and tool takes place by means of successive sparks occurring between them. The tool wear is a critical problem in EDM as the change in tool shape directly affects the final shape of the workpiece. In this paper, finite element analysis of tool wear in electrical discharge machining is carried out for copper tool. The input data required for simulation are taken from experimental details available in existing literature. For energy distribution factor, an empirical formula is used. The simulation results are compared and validated with experimental results which showed good agreement. Keywords: EDM, TWR, experiment, finite element analysis

INTRODUCTION The electrical discharge machining (EDM) process uses principle of spark erosion for material removal from workpiece and tool. At present, EDM is an extensively used process in industry for machining of materials which requires high precision. To run machine tools at their maximum level, there is a need to optimize process parameters affecting performance of process. Many researchers have tried different techniques for optimization of EDM process but the experimental optimization is not cost effective and consumes more time. Hence, finite element analysis can be used as a tool for process optimization and certain methodology should be established for that. The thermo-physical model was developed by Joshi and Pande for parametric studies of EDM process using finite element analysis [1]. Liu et al. used finite element method to simulate tool wear during small hole drilling in titanium alloy by EDM [2]. Mohanty et al. carried out thermal-structural analysis of EDM process to analyze effect of process parameters on performance measures [3]. For prediction of

recast layer, a numerical model was developed by Tan and Yeo based on multiple discharge approach in micro EDM [4]. Kansal et al. developed a finite element model to predict material removal rate in powder mixed electric discharge machining process [5]. In this work, experimental data are taken from available literature and used as input for finite element analysis (FEA) of tool wear in electrical discharge machining process.

EXPERIMENTAL DATA Table 1 shows experimental parameters and TWR from experiments as well as Patelâ&#x20AC;&#x2122;s model in which steel workpiece and copper tool were used [6]. These experimental parameters are used as input for modeling of EDM process.

THERMAL ANALYSIS OF EDM PROCESS Thermal analysis of EDM process is carried out to predict tool wear rate (TWR) using experimental data available in literature.

Page 18

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

An Experimental Study of Wear and Frictional Behaviour of Different Metal Pairs under Different Normal Loads Deependra Singh Patel*, Ashesh Tiwari Department of Mechanical Engineering, Institute of Engineering and Technology, Devi Ahilya Vishvavidyalaya, Indore, Madhya Pradesh, India Abstract In the present study, wear and friction coefficients of different material pairs, such as aluminium, brass, copper and steel, are investigated and compared experimentally. In order to do so, a pin-on-disc apparatus is used. Experiments are carried out when different types of pins such as aluminium, brass, copper and mild steel slide on different disc materials such as aluminium, brass, copper and mild steel. Experiments are conducted at normal load of 5, 10, 15 and 20 N, sliding velocity 1 m/s and relative humidity 70%. Variations of wear and friction coefficient at different normal load are investigated. Results show that wear and friction coefficient varies with normal load. The obtained results reveal that friction coefficient increases with the increase in normal load for most of the tested pairs and decreases for others. The magnitudes of friction coefficient are different for different material pairs depending on normal load. Moreover, the wear increases with the increase in normal load for all the tested pairs. Keywords: Friction coefficient, wear, normal load, aluminium, brass, copper, mild steel

INTRODUCTION In the past few years, numerous investigations have been carried out and several researchers observed that friction and wear depend on several parameters such as normal load, surface roughness, sliding velocity, relative humidity, lubrication etc. There have been also many investigations to explore the influence of type of material, temperature, stick-slip, contact geometry and vibration [1–13]. Normal load is the important parameter that dictates the tribological performance of metals and alloys. Copper and copper-based alloys are widely used in many engineering applications because of high thermal and electrical conductivity, very good corrosion and wear resistance and self-lubrication property [14, 15]. Copper-based alloys are used as bearing materials to achieve a high wear resistance [16]. Pure aluminium and aluminium-based alloys can be used in applications where corrosion is a problem. Aluminium alloys are used as bearing materials where low friction is required [17]. Wear resistance of Si added aluminium alloys is higher than that of the other aluminium alloys [18]. Aluminium, lead, tin, copper and

their alloys can be used as a coating material to steel bearing due to their superior wear properties [19–21]. Bearing materials are expected to have several good properties such as high load capacity, low friction coefficient, high corrosion resistance, high wear resistance and high heat conductivity. All of these properties significantly affect the fatigue and wear life [16]. In the high load regime, friction coefficient either increases or decreases with load for many metallic pairs. It is believed that due to a large amount of wear debris and increased surface roughening, friction force decreases [22, 23]. At loads from micro to nano-Newton range, friction coefficient may be very low when the contacting surfaces are very smooth [24, 25]. In the previous investigations, metals and alloys sliding against different pin materials showed different frictional properties under a range of operating conditions [26–29]. Despite these investigations, friction and wear of aluminium, brass, copper and mild steel sliding against aluminium, brass, copper and mild steel are yet

Page 23

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

Stress Analysis of Variable Thickness FGM Rotating Disks by Element based Material Gradation under Thermomechanical Loading Amit Kumar Thawait1,*, Lakshman Sondhi2, Shubhankar Bhowmick3, Shubhashis Sanyal4 1,2

Department of Mechanical Engineering, Shri Shankaracharya Technical Campus, Bhilai, Chhattisgarh, India 3,4 Department of Mechanical Engineering, National Institute of Technology, Raipur, Chhattisgarh, India

Abstract The present research work aims to analyze deformation and stresses, induced in functionally graded rotating disks of variable thicknesses. The disks are made of exponential functionally graded material, whose mechanical and physical properties vary in radial direction. Functionally gradation of the properties is achieved by element-based gradation. Uniform as well as variable thickness, namely concave profile, convex profile and linear varying profile rotating disks are analyzed for clamped-free and free-free boundary conditions. Disks are rotating in non-uniform temperature field, due to which thermomechanical elastic stresses induced in the disks. These stresses and resulting deformation, due to centrifugal force and uneven temperature distribution are evaluated and presented. Results obtained show that the deformation and stress fields in a rotating disk under thermomechanical loadings can be controlled by varying the thickness of the disk. Keywords: Functionally graded material (FGM), variable thickness rotating disk, element based gradation, thermoelastic analysis

INTRODUCTION Functionally graded materials (FGMs) are special composite materials that have continuous and smooth spatial variations of physical and mechanical properties. Functionally graded components, in recent years, are widely used in space vehicles, aircrafts, nuclear power plants and many other engineering applications. Machine elements in the fields of gas turbines, gears, turbomachinery etc. are the examples of rotating disks where thermomechanical loadings come into the picture. In such cases stresses due to centrifugal load and uneven temperature distribution, have important effects on the strength and safety of the components. Thus, control and optimization of stress and displacement fields can help to reduce the overall payload in industries. Optimization of the stress to strength ratio is done by varying the material property and thickness of the disk. Disks made up of functionally graded

materials and of variable thickness, have significant stress reduction over the disks made up of homogeneous material and of uniform thickness. Therefore, a higher limit speed is permissible for FGM disks. Literature review, although points towards the popularity of the area of investigation of disk stresses and deformation states, however, research on varying geometry rotating disk made of functionally graded material is scarce. Eraslan et al. (2003) has obtained analytical solutions for the elastic plastic stress distribution in rotating variable thickness annular disks [1]. Thickness of the disks has parabolic variation and the analysis is based on the Trescaâ&#x20AC;&#x2122;s yield criterion. Bayat et al. (2009) reported work on analysis of a variable thickness FGM rotating disk [2]. Material properties vary according to power law and the disk is subjected to both the mechanical and thermal loads. Afsar et al.

Page 32

Trends in Machine Design ISSN: 2455-3352(online) Volume 3, Issue 3 www.stmjournals.com

Failure Analysis of Bearing: A Review Pranav P. Bagdiya*, Ashok J. Keche Department of Mechanical Engineering, Maharashtra Institute of Technology, Aurangabad, Maharashtra, India

Abstract Ball and rolling element bearings are perhaps the most widely used components in industrial machinery. They are used to support load and allow relative motion inherent in the mechanisms involved, preventive measures and recommended corrections to enhance the life of the bearing. In this paper, the most widely referred mechanisms are reviewed and discussed, and their limitations are addressed. Heat flows within a bearing, scanning electron microscope (SEM), Fourier infrared transform spectroscopy (FTIR), high-frequency natural bearing resonance indicators (HFNBRI), and various modelling and simulation software such as ProE, Ansys and LabVIEW are also discussed in these papers. Keywords: Finite element method, rolling contact fatigue, ANSYS, phenolic composite, thermal analysis

INTRODUCTION The rolling bearing is a machinery component that plays a very important role, since it dominates the machine performance. If one of the bearings fails, not only the machine, but also the assembly line stops and the deriving costs may be extremely high. Bearings are one of the important machine elements used in many applications, which include rotating component. This supports another moving machine element permitting the relative motion between the rolling-element bearings consisting of balls or rollers positioned between raceways. Extreme operating condition of heavy loading, very high speed, and very high or low operating temperature leads to early bearing failure. Mostly the ball and roller bearing failures are caused by interference of the lubricant supply to the bearing or inadequate delivery of the lubricating oil to the raceway contact. Ball bearings can be divided into three categories, i.e. radial contact, angular contact, and thrust. Radial-contact ball bearings are designed to support radial loads. Angular contact bearings are designed to support combination of radial and axial loads. Thrust bearings are designed to support axial loads. Roller bearings have higher load capacities than ball bearings for a given size and are usually used in moderate

speed heavy duty applications. The preliminary types of roller bearings are cylindrical, needle, tapered, and spherical roller bearing. The service life of bearings is either as a period of time or as the total number of rotations before the occurrence of failures in the inner ring, outer ring or in rolling element (ball or roller) because of rolling fatigue, due to repeated stress. Rated life of bearing which is expressed as the period at which equipment or machine element fails under specified conditions of use, is given by its manufacturer. The service life of bearing differs from rated life, where bearing failure may be caused by poor lubrication, misalignment, and mounting damage before its actual life.

LITERATURE REVIEW Graney et al. addresses the purpose to briefly talk about how the high-frequency natural bearing resonance indicator, discrete frequency indicators (acceleration), acceleration time waveform characteristics, acceleration time waveform crest factor, and the velocity amplitude of bearing fault frequencies with respect to rolling element bearings can be integrated to assert the bearingâ&#x20AC;&#x2122;s health and the probability of a catastrophic failure [1]. This paper also introduces the multiple technologies and

Page 43

ISO: 9001Certified

ISSN 2455-3352 (Online)

STM Journals Empowering knowledge

Trends in

Machine Design

Free Online Registration

Septemberâ&#x20AC;&#x2019;December 2016 22

Energy /

/ Instrumentation /Science

GLOBAL READERSHIP STATISTICS

conducted

To g e t m o r e i n f o r m a t i o n : stmconferences.com

STM JOURNALS Scientific

Technical

Medical

www.stmjournals.com

(TMD)