Modeling the contact of stiff and soft bodies with a rigid support by short range force fields

Body impact-contact dynamics is a classical subject in mechanics. Most of the papers on the subject are based on a kinematical or impulse-exchange approach. In this paper a different approach has been adopted. It consists in assigning a constitutive description for the contact forces between the boundaries of bodies which get close to each other. In particular, a field of short range forces has been used to model the interaction between an affine body and the planar surface of a fixed rigid support. These forces are able to describe the impact, friction and adhesion allowing the body to have complex motions which look rather realistic. By an affine body we mean a body which undergoes affine, or homogeneous, deformations. Depending on the material, such a body can show very different behavior, from a quite rigid motion to a motion characterized by very large deformations. A soft body is assumed to be made of a viscous incompressible Mooney-Rivlin material. Though a microscopic model of surface interaction could be used in a multiscale approach, the description provided here is macroscopic only.