Equivalent impact system approach for elastoplastic impact analysis of dissimilar spheres

The dynamic response during normal elastoplastic impact of dissimilar spheres, i.e. spheres of different sizes and material composition, is investigated theoretically. A new modelling approach, called equivalent impact system approach (EISA), is developed to perform detailed investigation on the local compliance response and rigid body motion of each sphere during normal elastoplastic impact of dissimilar spheres. The EISA is validated using results obtained from conventional modelling of two spheres. Also, the coefficient of restitution for impact of materially-dissimilar spheres was investigated using an effective yield strength formulation proposed in this study. The results show that the effective yield formulation predicts experiments better than the commonly used minimum yield formulation.