A. Tasora, M. Anitescu, S. Negrini, D. Negrut, "A Compliant Visco-Plastic Particle Contact Model Based on Differential Variational Inequalities," Preprint ANL/MCS-P4013-0113, January 2013. [pdf]
This work describes an approach to simulate contacts between three- dimensional shapes with compliance and damping using the framework of the differential variational inequality theory. Within the context of nonsmooth dynamics, we introduce an extension to the classical set-valued model for frictional contacts between rigid bodies, allowing contacts to experience local compliance, viscosity, and plasticization. Different types of yield surfaces can be defined for various types of contact, a versatile approach that contains the classic dry Coulomb friction as a special case. The resulting problem is a differential variational inequality that can be solved, at each integration time step, as a variational inequality over a convex set.