Dan B. Marghitu is Professor in the Department of Mechanical Engineering at Auburn University. His specialty areas include impact dynamics, biomechanics, nonlinear dynamics, flexible multibody systems and robotics. He is the author of more than 60 journal papers and six books on dynamics, mechanical impact, mechanisms, robots and biomechanics.Mihai Dupac is a senior lecturer in Engineering Design in the School of Design, Engineering and Computing at Bournemouth University, UK. He obtained his Ph.D. in Mechanical Engineering at Auburn University, USA. His research interests are in the areas of design simulation & modelling, nonlinear dynamics, mechanisms and mechanical vibrations, and biomechanics. He has published over 50 journal and conference papers in these areas.