A variational integrator for the Discrete Element Method

A novel implicit integration scheme for the Discrete Element Method (DEM) based on variational integrator approach is presented. The numerical solver provides a fully dynamical description that, notably, reduces to an energy minimisation in quasi-static limit. detailed derivation of method presented Hookean contact model and tested against established open source DEM package that uses velocity-Verlet scheme. These tests compare results single collision, long-term stability statistical quantities ensembles particles. Numerically, proposed demonstrates equivalent accuracy method.