A compliant visco-plastic particle contact model based on differential variational inequalities

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 non-smooth 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.

► Problems with large number of parts with contacts are expressed as differential variational inequalities (DVIs).
► The same model can be adjusted to range from infinitely rigid contacts to compliant contacts.
► Optional damping and plasticization can be added to compliant contacts.
► The problem is solved with a spectral projected gradient method.
► Application can range from real-time simulations in robotics to complex granular flows.