Impact of Viscoplastic Bodies: Dissipation and Restitution

Abstract

A viscoplastic coefficient of restitution (COR) that accounts for nonfrictional sources of energy dissipation is determined for direct collision between hard compliant bodies. This COR incorporates effects of both irreversible elastic-plastic material (rate-independent) and viscoelastic (rate-dependent) behaviors. The COR is calculated based on a modified Maxwell model for compliance of the bodies in the small deforming region around the initial contact point. Modifications to the Maxwell model incorporate the effects of plasticity and viscoelasticity, so the calculated COR gives a value that considers both hysteresis due to the plastic deformation and viscoelastic (rate-dependent) sources of energy dissipation during collision.