Qualification: 
Ph.D
r_ajith@cb.amrita.edu

Dr. Ajith Ramesh currently serves as Associate Professor at department of Mechanical Engineering, School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore. His areas of research include FEM, Creep and Faliure Analysis, Contact Mechanics and Composite Structures.

Education

  • 2009: Ph.D. in Mechanical Engineering
    The University of North Carolina at Charlotte, North Carolina, USA.
  • 2005: MS in Mechanical Engineering (MSME)
    The University of North Carolina at Charlotte, North Carolina, USA.
  • 2000: B.Tech. in Mechanical (Production) Engineering
    The University of Kerala, India.

Experience

Year Affiliation
July 2009 - Present Faculty, Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham, Coimbatore
Feb 2006 – May 2009 Research Assistant in the area of Computational Solid Mechanics leading to the successful completion of Ph.D. in Mechanical Engineering from The University of North Carolina at Charlotte
  • The research project titled, “Modeling the Creep Behavior of Torsional Springs”, was funded by The Lawrence Livermore National Laboratory (LLNL)
  • The results are used as a benchmark by LLNL for their classified applications
Aug 2002 - Dec 2004 Teaching Assistant in Statics, Dynamics, Mechanics of Solids, Materials Science, Fluid Mechanics and Machine Design at Department of Mechanical Engineering, University of North Carolina at Charlotte
  • Experience in teaching under-graduate (B.S) level classes, conducting examinations, and advising students
Aug 2004 - Feb 2006 Teaching Assistant , in Material Science Laboratory at Department of Mechanical Engineering, University of North Carolina at Charlotte
  • Experience in performing experiments to capture material properties, and conducting lab sessions for the undergraduate students
Jan 2005 - May 2005 Industrial Intern at Duke Power in the area of Supply Chain Management
  • Experience in handling decorative and specialty lighting supply chain at Duke’s operating centers, using Systems Integration techniques
Feb 2001 - Jul 2002 Trainee Software Consultant in COOL: Plex at Sonsie Technologies Ltd, Bangalore, India.
  • Experience in handling software projects using COOL: Plex (CA) - a template (pattern) based, platform independent, e-business development tool having multidisciplinary applications like web-designing, finance, banking, engineering and other business solutions

Areas of Research Interest

Computational Modeling & Analysis (FEM) and Experimental Evaluation of non-linear, coupled, large deformation problems:

  • Machining and Machinability of Materials (Hard-to-machine materials: Titanium-based alloys, AUSC alloys)
  • Metal Forming (Hot & Cold Rolling, Flow-forming, Hydro-forming, Punching, etc.)
  • Creep, Fatigue, Fracture and Failure
  • Wear of coated systems (Polymer-coated sliding bearings, bone implants, etc.)
  • Spring-based energy storage systems

Development of Innovative and Cost-effective design solutions

Research

Sponsored Projects

Invited Talks

  1. Faculty Development Program at Department of Mechanical Engineering, Sri Krishna College of Engineering and Technology, Kuniamuthur, Coimbatore, in “How to Effectively Teach Solid Mechanics?”
  2. Mechanical Engineering Seminar Series at Department of Mechanical Engineering, Sri Krishna College of Technology, Kuniamuthur, Coimbatore, in “Finite Element Methods - Theory and Applications”.
  3. Mechanical Engineering Seminar Series at Department of Mechanical Engineering, Royal College of Engineering and Technology, Thrissur, Kerala, in “Mechanics of Solids”.

Reviewer – Journals, Conferences and Books

  1. International Journal of Analytical, Experimental, and Finite Element Analysis.
  2. International Journal of Mechanics and Design.
  3. International Journal of Automation.
  4. International Journal of Production Engineering.

Conferences – Organized

  1. Organized Faculty Development Programs, Workshops, and Student Interaction Lectures under the Fulbright Specialist Scholar program sponsored by the US-India Educational Foundation in January 2018.
  2. International Conference on Simulation, Modeling, and Analysis (COSMA), co-hosted by Amrita Vishwa Vidyapeetham, Coimbatore and NIT-Calicut in December, 2011.

Conferences, Seminars and Workshops - Participated

  1. Remote Center Coordinator for the IIT-Bombay ISTE Workshop on ‘Pedagogy for Effective use of ICT in Engineering Education’, in Jan 2015.
  2. Participated and presented paper at the Eleventh ISAMPE National Conference on Composites organized by Amrita Vishwa Vidyapeetham, in Nov 2012.
  3. Organizing committee member, and presented research papers at COSMA-2011 International Conference, co-hosted by Amrita Vishwa Vidyapeetham and N.I.T-Calicut, in Dec 2011.
  4. Organized a workshop on “Developing Successful Research Proposals” at Amrita in Jan 2010.
  5. Participated in the Sixth International Conference on Precision, Meso, Micro, and Nano- Engineering, organized by Amrita Vishwa Vidyapeetham, P.S.G. College of Technology, and University of North Carolina at Charlotte, USA, in December 2009.
  6. Presented a research paper at the Abaqus Users’ Conference at Dassault Systems Simulia, Newport, Rhode Island, USA, in May 2008.

Other Academic/Non-Academic Activities

  1. Member of the Board of Studies for B.Tech (2010-2013) and M.Tech programs (2010-till date) at Amrita.
  2. Course Coordinator and Class Advisor for the M.Tech – Engineering Design program.
  3. M.Tech – Engineering Design, Projects Coordinator and Review Panel member.
  4. Review Panel member for B.Tech – Mechanical Engineering projects.
  5. Doctoral Committee member for 1 internal (Amrita) and 2 external (Anna Univ.) Ph.D. committees.
  6. Member of Ph.D. admissions panel for the department of Mechanical Engineering.
  7. Member of the M.Tech admissions panel for the department of Mechanical Engineering.
  8. Volunteer of Amala Bharatham – a world-wide cleaning drive organized by the Mata Amritanandamayi Math.
  9. Organizing committee member and coordinator for several technical and non-technical events at the university.

Publications

Publication Type: Journal Article

Year of Publication Title

2018

C.S. Sumesh and Dr. Ajith Ramesh, “Numerical modelling and optimization of dry orthogonal turning of Al6061 T6 alloy”, Periodica Polytechnica Mechanical Engineering, vol. 62, pp. 196-202, 2018.[Abstract]


In this paper, the influence of machining parameters, Cutting Speed, Feed Rate, and Depth of cut, on surface finish during dry orthogonal turning of Al 6061 - T6 alloy, is studied using the response surface methodology (RSM). This paper proposes a unique way to predict the surface finish in turning, using the effective plastic strain (PEEQ) values obtained from the simulations. A comprehensive finite element model was proposed to predict the surface finish accurately, by correlating the variance of the PEEQ. The Johnson-Cook damage model is used to define the damage criteria and Johnson-Cook material model is used to explain the material constitutive behavior. A dynamic, explicit method is used along with the Adaptive Lagrangian-Eulerian (ALE) method to predict material flow accurately. The influence of machining parameters was studied by assuming Central Composite Design (CCD). The output response, PEEQ, was fitted into analytical quadratic polynomial models using regression analysis, which shows that feed rate was the most dominant factor for PEEQ than the other parameters considered in this study. Using the individual desirability function method, the objective, optimal setting of the machining parameters was obtained for better surface finish. © 2018 Budapest University of Technology and Economics. All rights reserved.

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2016

M. Haridas, G. Gopal, Dr. Ajith Ramesh, and R.K. Katta, “Modelling and simulation of single and multi-pass flow forming to investigate the influence of process parameters on part accuracy”, International Journal of Manufacturing Research, vol. 11, pp. 274-289, 2016.[Abstract]


Flow forming is an incremental forming process used for making long, thin-walled seamless tubes with high strength and dimensional accuracy. This is carried out by compressing the pre-formed tube using one or more rollers, leading to the plastic flow of material in the radial, axial, and tangential directions. This ultimately results in reduction in thickness and elongation of the tube. In order to achieve the required accuracy and to reduce the shop floor costs, a better understanding of the influence of process parameters on part geometry, deformation mechanism, and stress-strain patterns will be required. This paper describes the development of a detailed finite element model, using Abaqus/Explicit, to accurately simulate the flow forming process for AISI-1045 MC-Steel, and attempts to predict the influence of process parameters like axial stagger, feed ratio, and percentage reduction, on output parameters like ovality, diametral growth, and spring back. The effect of multi-pass on surface finish is also investigated.

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2015

Dr. Ajith Ramesh, Sumesh, C. S., Abhilash, P. M., and Rakesh, S., “Finite Element Modelling of Orthogonal Machining of Hard to Machine Materials”, International Journal of Machining and Machinability of Materials, vol. 17, pp. 543-568, 2015.[Abstract]


This paper presents a detailed finite element model to predict deformation and other machining characteristics involved in high-speed orthogonal machining (cutting speed > 54 m/min) of hard-to-deform materials like Ti6Al4V. The influence of various cutting parameters like feed rate, spindle speed, and rake angle, on the output parameters like cutting force and surface finish, was analysed. The paper tries to relate the degree of surface finish with the variance of the effective plastic strain. The Johnson-Cook material model is used to describe the material constitutive behaviour, and the Johnson-Cook damage model is used to establish the damage criteria. Due to the high machining costs associated with the titanium alloy, the model is first validated using aluminium alloy (Al2024-T351), and the same model is then extended to predict the results for titanium alloy. The matrix for the design of experiments (DOE) considers a full factorial approach, with about 48 simulations, for a proper understanding on the influence of the major machining parameters. A dynamic, explicit integration scheme is used along with the arbitrary Lagrangian-Eulerian (ALE) technique to accurately predict material flow. This paper also presents a unique method to tackle the commonly encountered numerical issues involved in modelling self-contact. More »»

2012

K. Devarajan, Dr. Ajith Ramesh, and K Prakash Marimuthu, “FEM Analysis of Effect of Rolling Parameters on Cold Rolling Process”, Bonfring International Journal of Industrial Engineering and Management Science, vol. 2, no. 1, pp. 35-40, 2012.

2011

R. V. Prakash, Arunkumar, S., and Dr. Ajith Ramesh, “Spherical Indentation of Nickel Thin Flim on Steel-4340 Substrate”, International Mechanical Engineering Congress and Exposition (IMECE-2011), ASME, vol. 3, p. 745, 2011.[Abstract]


In this paper, finite element simulations of spherical indentation of Nickel thin film on Steel-4340 are studied for single and multiple cycle of indentation as well. The objective was to understand the mechanics of coated systems, from load-displacement (P-h) curves, stress distribution in the film and the effect of substrate yield strength on the indentation response. The loading portion of P-h curve showed displacement bursts and the reason for this is investigated. A transition in the deformation behavior of the film from Hertz-type to flexure was observed for a normalized indentation depth of h/tf ≈0.2. The influence of coating–substrate properties on P-h curve is also investigated for different h/tf ratios and yield strains. Attempts are also made to explore the possibility of understanding the creep-fatigue behavior of coated specimen subjected to cyclic indentation at room temperature from Indentation depth v/s time, Indentation depth v/s number of cycles and Plastic dissipation energy v/s number of cycles curve.

Copyright © 2011 by ASME

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2011

R. V. Prakash, Arunkumar, S., and Dr. Ajith Ramesh, “Spherical indentation of nickel thin film on steel - 4340 substrate”, ASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011, vol. 3, pp. 745-750, 2011.[Abstract]


In this paper, finite element simulations of spherical indentation of Nickel thin film on Steel-4340 are studied for single and multiple cycle of indentation as well. The objective was to understand the mechanics of coated systems, from load-displacement (P-h) curves, stress distribution in the film and the effect of substrate yield strength on the indentation response. The loading portion of P-h curve showed displacement bursts and the reason for this is investigated. A transition in the deformation behavior of the film from Hertz-type to flexure was observed for a normalized indentation depth of h/tf≈0.2. The influence of coating-substrate properties on P-h curve is also investigated for different h/tf ratios and yield strains. Attempts are also made to explore the possibility of understanding the creep-fatigue behavior of coated specimen subjected to cyclic indentation at room temperature from Indentation depth v/s time, Indentation depth v/s number of cycles and Plastic dissipation energy v/s number of cycles curve.

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Publication Type: Conference Proceedings

Year of Publication Title

2013

Dr. Ajith Ramesh, M. P. Hari Prasad, and Renganathan, K., “Nonlinear Visco-Elastic Stress Analysis of a Circular Perforated Solid Propellant Grain”, International conference on Computer Aided Engineering (CAE). IIT-Madras, Chennai, 2013.

2012

D. Karuppannan, Sivaraman, V., Kotresh M Gaddikeri, Ramesh Sundaram, and Dr. Ajith Ramesh, “Effect of Tufting on Mechanical Properties of Laminated Composites”, Eleventh ISAMPE National Conference on Composites. Amrita Vishwa Vidyapeetham, Coimbatore, pp. 47-54, 2012.

2011

Dr. Ajith Ramesh, Devarajan K, and K, P. Marimuthu, “Finite Element Modeling of the Cold Rolling Process and Optimization using Genetic Algorithm”, International Conference on Simulation, Modeling, and Analysis (COSMA). Amrita Vishwa Vidyapeetham, Coimbatore and NIT-Calicut., 2011.

2011

Dr. Ajith Ramesh, Raghu V. Prakash, Arun Kumar S, and Dhayanidhi N, “Contact Stress-Strain and Wear Analysis of some Thermo-Plastics on Zerodur Glass”, International Conference on Simulation, Modeling, and Analysis (COSMA). Amrita Vishwa Vidyapeetham, Coimbatore and NIT-Calicut., 2011.

2011

R. V. Prakash, Arunkumar, S., and Dr. Ajith Ramesh, “Spherical Indentation of Nickel Thin Flim on Steel-4340 Substrate”, International Conference on Advances in Materials and Techniques for Infrastructure Development (AMTID), vol. 17. NIT-Calicut, pp. 543-568, 2011.[Abstract]


In this paper, finite element simulations of spherical indentation of Nickel thin film on Steel-4340 are studied for single and multiple cycle of indentation as well. The objective was to understand the mechanics of coated systems, from load-displacement (P-h) curves, stress distribution in the film and the effect of substrate yield strength on the indentation response. The loading portion of P-h curve showed displacement bursts and the reason for this is investigated. A transition in the deformation behavior of the film from Hertz-type to flexure was observed for a normalized indentation depth of h/tf ≈0.2. The influence of coating–substrate properties on P-h curve is also investigated for different h/tf ratios and yield strains. Attempts are also made to explore the possibility of understanding the creep-fatigue behavior of coated specimen subjected to cyclic indentation at room temperature from Indentation depth v/s time, Indentation depth v/s number of cycles and Plastic dissipation energy v/s number of cycles curve.

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2010

Pradip P Sairam, Sreeja M R, Dr. Ajith Ramesh, and Dr. Meera Balachandran, “Mechanical And Visco-Elastic Properties Of Silicone Rubber – Nanoclay Composites And Its Application In Vibration Damper”, Proceedings of International Conference on Manufacturing Science and Technology (ICMST 2010). Indian Institute of Space Science and Technology and Materials Research Society of India, Thiruvananthapuram, 2010.

2008

Dr. Ajith Ramesh, Bose, K., and Lawton, K. M., “Modeling the Creep Behavior of Torsional Springs”, Abaqus Users’ Conference, Dassault Systems Simulia, Newport. The University of North Carolina at Charlotte, Rhode Island, USA, pp. 395-410, 2008.[Abstract]


This dissertation presents a detailed model of the ‘overall’ behavior of Torsional springs. Torsional springs (also called ‘Clock’ springs) are a kind of spiral springs which are supposed to provide a certain torque when wound-up to a certain rotation. However, it is observed that the moments that are developed relax when the springs are kept loaded over long periods of time. The research presented here is an attempt to investigate this behavior by identifying the role played by the various influencing parameters.

The dissertation focuses on the development of a detailed component-level finite element model to investigate the instantaneous moment-rotation response as well as the long-term (time-dependant) structural response of a torsional spring. Torsional springs belong to a class of planar spiral springs that are commonly made out of Elgiloy - an alloy of Cobalt, Chromium, Nickel, and Iron. Elgiloy has very high yield strength, and is commonly used as a spring material in analog clocks. In addition, the research also aims at developing a better understanding of the dependence of the response of the spring on the different design parameters that define its geometry and material properties. Frictional contact, large deformations, and nonlinear material behavior (plasticity and creep) are among the major challenges that need to be resolved in order to obtain a thorough understanding of the problem. The modeling effort also focuses on understanding the experimentally-observed hysteresis associated with a cyclic moment versus rotation response, as well as the development of simple analytical models which can approximately describe the structural response of a typical torsional spring.

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Honors & Awards

  1. Awarded scholarship/grant by The Lawrence Livermore National Laboratory, U.S.A., as a Research Assistant towards successful completion of Ph.D. research at UNC Charlotte.
  2. Awarded scholarship by National Science Foundation (N.S.F), U.S.A., to attend a short course in Nano-Scale Design of Materials which was organized by the Summer Institute on Nano-Mechanics and Materials, during Aug 25 - 29, 2003, at The North-Western University, Chicago.
  3. Awarded the 3rdBest Research Presentation at the Graduate Research Fair at UNC Charlotte in Mar 2008.
  4. Chaired 2 sessions of the International Conference, ICONAMMA-2016 at Amrita Vishwa Vidyapeetham, Bangalore campus.
  5. Chaired 2 conference sessions for COSMA-2011 organized by Amrita & NIT, Calicut
  6. Successfully completed 2 under-graduate projects of social relevance, with seed funding from Mata Amritanandamayi Math.

Professional Bodies

  1. Member of the Student Chapter for Precision Engineering at UNC Charlotte, NC, USA.

Student Guidance

Doctoral Students

  1. Mr. Sumesh C. S. – “Finite Element Modeling and Experimental Evaluation of Deformation and Chip Morphology in Machining Processes involving Hard to Machine Materials”.
  2. Mr. Unnikrishnan D. – “Modeling the Effect of Blade Shape on Performance and Structural Integrity of Vertical Axis Wind Turbines”.

Masters Students

  1. 9 M.Tech - Engineering Design students completed their thesis successfully in the period 2014 – 2018.
  2. 16 M.Tech - Engineering Design students completed their thesis successfully in the period 2009 – 2014.

Other Activities

  • Captain and active member of the Faculty Cricket team for the department
  • Active participant in cultural and sports & games activities at the university