Coefficients of restitution for elastoplastic oblique impacts

The paper presents results of a finite element analysis of both elastic and elastoplastic oblique impacts of a sphere with a target wall using the DYNA3D code. For elastic oblique impacts, the results are in complete agreement with previous publications. For elastoplastic oblique impacts, the rebound kinematics depend on the normal coefficient of restitution, which is conventionally assumed to be a function of the normal impact velocity irrespective of the impact angle. The results of the finite element simulations of elastoplastic impacts demonstrate that this is not the case.