Qualification: 
Ph.D, M.Tech, B-Tech
b_santhosh@cb.amrita.edu

Dr. Santhosh B. currently serves as Assistant Professor (SG) at the Department of Mechanical Engineering, School of Engineering, Coimbatore Campus. His areas of research include Linear and Nonlinear Vibrations, System Dynamics and Control and Random Vibrations.

Education

  • 2015

Ph.D (Mechanical Engineering/ Machine Design)
IIT Madras, Chennai, India

  • 2005

M.Tech (Machine Dynamics)
IIT Madras, Chennai, India

  • 1996

B.Tech (Mechanical Engineering)
College of Engineering Trivandrum, Kerala University

Teaching

(Theory Courses Handled)

  • 2014 - 2015 ODD :

MEC 100 Engineering Mechanics (B.Tech.)

  • 2015 - 2016 ODD :

MEC 302Dynamics of Machinery (B.Tech.)

  • 2015 - 2016 ODD :

MEC 362Computational Methods in Engineering (B.Tech.)

  • 2015 - 2016 EVEN :

MEC365Theory of Vibrations (B.Tech.)

  • 2016 - 2017 ODD :

MEC362Computational Methods in Engineering (B.Tech.)

  • 2016 - 2017 ODD :

16MA611Mathematical Methods for Engineering Design (M.Tech.)

  • 2016 - 2017 ODD :

16AT624Intro. to programming using MATLAB (M.Tech.)

  • 2016 - 2017 EVEN :

MEC212 Kinematics of Machines (B.Tech.)

  • 2017 - 2018 ODD :

16MA611Mathematical methods for Engineering Design (M.Tech.)

  • 2017 - 2018 ODD :

MEC239Modeling and simulation of Engineering Systems (B.Tech.)

  • 2017 - 2018 ODD :

16AT624Intro. to programming using MATLAB (M.Tech.)

  • 2017 - 2018 EVEN :

15MEC212 Kinematics of Machines (B.Tech.)

Research

My research is focused towards understanding and exploiting the dynamics of physical and engineering systems with nonlinear effects. Traditional design practices neglected the influence of nonlinearity due to the non-existence of a generalized computational frame-work and the difficulty in understanding the complex dynamics. With the advancement in computational power, efficient algorithms and experiments, there is a paradigm shift in the conventional thought process and lead to a new research direction "`Exploitingthe nonlinear behavior in physical systems to improve its performance"'. My research is in line with the above thought process and it was understood that careful inclusion of nonlinearities in physical systems can improve the performance of the systems compared to the linear counterpart. This is demonstrated through real world applications such as bistable systems for energy harvesting, negative stiffness vibration isolation mechanism and multi-functional energy harvesting models.I am part of the thrust area group “Computational Nonlinear Dynamics and Vibrations” at Amrita Vishwa Vidyapeetham.

Research Interests

  • Nonlinear Dynamics
  • Energy harvesting from dynamical systems
  • Multi-functional energy harvesting methods
  • Nonlinear vibration absorbers and isolators
  • Fluid structure interaction problems

Currently my group working on the following important research problems

  • Enhancing the performance of bistable energy harvesting devices through elastic magnifiers and elastic discontinuous constraints
  • Analysis of multi-functional energy harvesting models with nonlinear energy sink (NES) using nonlinear normal mode (NNM) framework
  • Entrainment and bifurcation studies in disc brake models for better understanding of brake squeal
  • Development of negative stiffness vibration isolation mechanisms for precision instruments

Publications

Publication Type: Conference Paper

Year of Publication Title

2018

P. Ashok, C. Jawahar Chandra, P. Neeraj, and Dr. Santhosh B., “Parametric Study and Optimization of a Piezoelectric Energy Harvester from Flow Induced Vibration”, in IOP Conference Series: Materials Science and Engineering, 2018, vol. 310.[Abstract]


Self-powered systems have become the need of the hour and several devices and techniques were proposed in favour of this crisis. Among the various sources, vibrations, being the most practical scenario, is chosen in the present study to investigate for the possibility of harvesting energy. Various methods were devised to trap the energy generated by vibrating bodies, which would otherwise be wasted. One such concept is termed as flow-induced vibration which involves the flow of a fluid across a bluff body that oscillates due to a phenomenon known as vortex shedding. These oscillations can be converted into electrical energy by the use of piezoelectric patches. A two degree of freedom system containing a cylinder as the primary mass and a cantilever beam as the secondary mass attached with a piezoelectric circuit, was considered to model the problem. Three wake oscillator models were studied in order to determine the one which can generate results with high accuracy. It was found that Facchinetti model produced better results than the other two and hence a parametric study was performed to determine the favourable range of the controllable variables of the system. A fitness function was formulated and optimization of the selected parameters was done using genetic algorithm. The parametric optimization led to a considerable improvement in the harvested voltage from the system owing to the high displacement of secondary mass. © Published under licence by IOP Publishing Ltd.

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2018

Ratnesh Kumar Singh, K. Devarajan, and Dr. Santhosh B., “Numerical solution for stick-slip oscillator with geometric non-linearity”, in IOP Conference Series: Materials Science and Engineering, 2018, vol. 310.[Abstract]


Linear spring mass framework controlled by moving belt friction have been subjected to various examinations. Dynamical attributes like amplitude and frequency of oscillations have been in a big way studied along by the whole of the different approach mechanisms for this model. Along by all of the dynamical characteristics, bifurcation structures also have been investigated. On the other hand, the corresponding self-excited SD oscillator has not instructed comparable attention. This complimentary presents the numerical investigation of the character of a self-excited SD oscillator resting on a belt moving with consistent speed and excited by dry friction. The moving belt friction is displayed as the Stirbeck friction (friction first decreases and then increase smoothly with interface speed) to figure the scientific model. It is demonstrated that the pure-slip oscillation phase influenced by system parameter α. The influence of different system parameters on the dynamical characteristics was alongside considered. © Published under licence by IOP Publishing Ltd.

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2018

Kabilan S, Vaishnav V, Gowtham E, and Dr. Santhosh B., “Dynamics of a Single Degree of Freedom Clutch Damper System with Multiple Discontinuous Nonlinearities”, in IOP Conference Series: Materials Science and Engineering, 2018, vol. 310.

2017

Alwin Thomas, B. Balaram, and Dr. Santhosh B., “Entrainment in multi degree of freedom discontinuous system with application to disc brakes”, in Int. Conference on Vibration problems (ICOVP 2017), IIT Guwahati, 2017.

2017

Pooja More, Dr. Santhosh B., and Amol Jain, “Analysis of Radiator Mounting Bracket Design and Derivation of Transfer Function to Predict Modal Frequencies Based on Parametric Study”, in Int. Conf. on advances in Materials and Manufacturing applications, IconAmma 2017, Amrita Vishwa Vidyapeetham, Bangalore, 2017.

2017

Rasil Raj P V and Dr. Santhosh B., “A comparative study on the primary system response and energy harvesting from linear and nonlinear tuned vibration absorbers”, in Int. Conference on Vibration problems (ICOVP 2017), IIT Guwahati, 2017.

2016

K. Mukund and Dr. Santhosh B., “Dynamics of a Stable-quasi-zero-stiffness Isolator Mechanism using Multi Harmonic Balance Method”, in International Conference on systems, energy and environment, (ICSEE 2016), College of Engineering, Kannur, Kerala, 2016.

2016

Dr. Santhosh B. and .Narayanan, S., “Reduced order models of dry friction damped systems with contact interface model”, in XXIV ICTAM, Montreal, Canada , 2016.

2015

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Discontinuity induced bifurcation in nonlinear oscillators”, in 12th Int. Conference on Vibration Problems (ICOVP-2015), IIT Guwahati, India, 2015.

2015

Dr. Santhosh B. and Subin Das, “Energy Harvesting from Nonlinear Vibration Absorbers”, in 12th Int. Conference on Vibration Problems (ICOVP-2015), IIT Guwahati, India, 2015.

2015

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Discontinuity induced bifurcations in Nonlinear Systems.”, in IUTAM Symposium on Analytical Methods in Nonlinear Dynamics, Frankfurt, Germany , 2015.

2015

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Discontinuity induced bifurcations in higher dimension Filippov systems.”, in Int. Conference on Engineering Vibration (ICOEV 2015), Slovenia, 2015.

2014

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Nonlinear Dynamics of a two degree of freedom Oscillator with a Snap Through Mechanism”, in 8thEuropean Nonlinear Dynamics Conference (ENOC 2014), Vienna, Austria, 2014.

2013

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Nonlinear Dynamics of Shrouded Turbine Blade System with Impact and Friction”, in 11th Int. Conference on Vibration Problems (ICOVP-2013), Lisbon, Portugal , 2013.

2012

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Dynamics of Oscillators with Continuous and Discontinuous Nonlinearities by Harmonic Balance and Path following”, in XXIII Int .Congress of Theoretical and Applied Mechanics (ICTAM 2012), Beijing, China, 2012.

Publication Type: Journal Article

Year of Publication Title

2018

Dr. Santhosh B., “Dynamics and performance evaluation of an asymmetric nonlinear vibration isolation mechanism”, Journal of the Brazilian Society of Mechanical Sciences and Engineering, vol. 40, no. 169, 2018.[Abstract]


In this work, the dynamics and performance of a harmonically excited asymmetric nonlinear vibration isolation mechanism is investigated using the multi harmonic balance method (MHBM). Asymmetry in the system is introduced in the form of a constant load along with the harmonic excitation. Instead of a truncated cubic nonlinear system considered in the previous works, the fully nonlinear system without any approximation is considered in this study. The MHBM framework considered in this paper is a systematic and computationally efficient method to generate periodic solutions of any order, continue their branches, identify stable, and unstable branches along with the types of bifurcations. Dynamics of the system is investigated with forcing frequency and forcing amplitude as the parameters. With an increase in the value of the constant load, the response diagram shows double folding with softening and hardening behavior and multiple jumps, disappearance of certain types of bifurcations, loss of stability of the periodic solutions, existence of higher order periodic solutions, and chaotic solutions. The transmissibility plots in the presence of the constant load show substantial deterioration in the vibration isolation capability of the isolation system. A comparison of the fully nonlinear system and the truncated cubic system is performed at the end to show that the solutions are qualitatively same but quantitatively different which is an important aspect in practical applications of isolation systems. © 2018, The Brazilian Society of Mechanical Sciences and Engineering.

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2016

Dr. Santhosh B. and Subin Das, “Energy Harvesting from Nonlinear Vibration Absorbers”, Procedia Engineering, vol. 144, pp. 653-659, 2016.

2016

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Discontinuity induced bifurcations in nonlinear systems”, Procedia IUTAM, vol. 16, pp. 219-227, 2016.

2015

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Nonlinear Dynamics of Shrouded Turbine Blade System with Impact and Friction”, Applied Mechanics and Materials, vol. 706, pp. 81-92, 2015.[Abstract]


Dry friction dampers are passive devices used to reduce the resonant vibration amplitudes in turbine bladed systems. In shrouded turbine blade systems, in addition to the stick- slip motion induced by dry friction during the contact state in the tangential direction, the interface also undergoes intermittent separation in the normal direction. The problem can thus be treated as a combination of impact and friction. In this work, the dynamics of dry friction damped oscillators which are representative models of dry friction damped bladed system is investigated. A one dimensional contact model which is capable of modeling the interface under constant and variable normal load is used. The steady state periodic solutions are obtained by multi - harmonic balance method (MHBM). Frequency response plots are generated for different values of normal load using the arc length continuation procedure. The MHBM solutions are validated using numerical integration. A single degree of freedom (dof) model under constant normal load with constant and variable friction coefficients, a dry friction damped two dof system under constant normal load and a two dof system under variable normal load are investigated. In the presence of variable normal load, the system shows multivalued frequency response and jump phenomenon. The optimal value of the normal load which gives minimum resonant response is also obtained.

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2014

Dr. Santhosh B., C Padmanabhan, and S Narayanan, “Numeric-analytic solutions of the smooth and discontinuous oscillator”, International Journal of Mechanical Sciences, vol. 84, pp. 102–119, 2014.[Abstract]


Earlier works on the smooth and discontinuous (SD) oscillator concentrated mainly on the time domain analysis using analytical, semi-analytical and numerical integration methods. In this paper, the frequency domain analysis of the SD oscillator subjected to harmonic excitation which is as important and giving further insight into the dynamics is carried out. Multi-Harmonic Balance Method (MHBM) in combination with arc length continuation is used to obtain the periodic solutions and their branches in the frequency domain for different values of the smoothing parameter α and exciting frequency ω . Stability of the periodic motions and bifurcation behavior are analyzed using the Floquet theory. For the discontinuous case, the oscillator is treated as a Filippov system and an event driven numerical integration method is used to obtain the response. For α>1, the dynamics of the SD oscillator is similar to that of the hardening Duffing oscillator, for α=1, it is like that of the Ueda oscillator and for 0<α<1 it is like that of the Duffing oscillator with double well potential. The SD oscillator exhibits period 1 solutions, higher order periodic solutions, chaotic solutions through symmetry breaking bifurcations, period doubling and boundary crises in different parameter ranges. Chaos is observed over a larger frequency range interspersed by narrow windows of higher order periodic solutions

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2013

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Periodic response and bifurcations of a smooth and discontinuous oscillator by harmonic balance method”, ADVANCES IN VIBRATION ENGINEERING, vol. 12, pp. 401–412, 2013.

Publication Type: Conference Proceedings

Year of Publication Title

2011

Dr. Santhosh B., S Narayanan, and C Padmanabhan, “Periodic Response and Bifurcations of a Smooth and Discontinuous Oscillator by Harmonic Balance Method”, 7th International conference on Vibration Engineering and Technology of Machinery (VETOMAC VII). Shanghai, China, 2011.

Workshops Conducted

  • Conducted a two-day workshop on Introduction to Nonlinear Dynamics, Theory and Computation, on January 27-28, 2017. This was attended by nearly 70 participants include UG, PG, PhD scholars, faculty members from all the three campuses.
  • Two-day workshop on Introduction to MATLAB for M.Tech Engineering Design and Automotive Engineering students. March 8-9, 2016.

Expert Lecture Delivered

  • Delivered a talk on “Energy Harvesting from Vibration Systems” College of Engineering, Kannur, Kerala on August 26, 2016.
  • Delivered a lecture on “Fundamentals of Nonlinear Vibrations”, AICTE sponsored faculty development program on Fundamentals of Vibration- Measurement, Analysis and Control at St. Joseph Engineering College, Chennai on November 6, 2017.