Impacts between stiff solid bodies typically involve brief contact interactions, large forces, large accelerations, finite changes in velocities, and tiny displacements compared to before- and after-impact displacements. Such impact interactions can be summarised using impulse-momentum relations, wherein if the impulse is known then the momentum change can be computed accurately. However, the impulse is not known and must be modelled or predicted using other information. The oldest and simplest approach in this direction is that of the coefficient of restitution, a rebound parameter introduced by Newton. However, to date, there is no simple restitution model that accounts explicitly (if approximately) for vibrations during the impact that involve several sub-impacts within one macroscopic interaction. Professor Anindya Chatterjee first talked about detailed numerical simulations of impacts between a Hertzian ball and some Euler-Bernoulli beams, wherein such vibrations are modelled in detail. He then described impulse-momentum level modelling of the same impacts using a conceptually much simpler model, which gives surprisingly good results for the average behaviour over a range of impacts. As far as Professor Chatterjee's research is concerned, no comparable modelling approach exists in the literature.

Anindya Chatterjee got his BTech in Mechanical Engineering from IIT Kharagpur in 1989, concurrent masters degrees in Engineering Mechanics and in Applied Mathematics from the University of Florida in 1993, and his PhD in Theoretical and Applied Mechanics from Cornell University in 1996. He was a Post Doctoral Fellow at Penn State University until early 2000, when he joined the Mechanical Engineering Department at IISc Bangalore. He moved to IIT Kharagpur in 2009 and then to IIT Kanpur in 2012. His research interests are broad, within the general areas of dynamics, vibrations, solid mechanics and applied mathematics. His teaching interests are in the same areas. He is a Fellow of the Indian National Academy of Engineering and the National Academy of Sciences, India.