A contact dynamics approach to the Granular Element Method

•We develop a new contact dynamics approach to the Granular Element Method (CD–GEM).•CD–GEM combines shape flexibility using NURBS with implicit time discretization.•We develop a novel separating hyperplane algorithm to simplify contact detection.•CD–GEM performs robustly with rigid particles in the quasi-static and flow regimes.•CD–GEM significantly simplifies current CD approaches while maintaining performance.

We present a contact dynamics (CD) approach to the Granular Element Method (GEM) Andrade et al. (2012) [1], abbreviated here as CD–GEM. By combining particle shape flexibility through Non-Uniform Rational Basis Splines, properties of implicit time-integration discretization (e.g., larger time steps) and non-penetrating constraints, as well as a reduction to a static formulation in the limit of an infinite time step, CD–GEM targets system properties and deformation regimes in which the classical discrete element method either performs poorly or simply fails; namely, in granular systems comprising of rigid or highly stiff angular particles and subjected to quasi-static or intense dynamic flow conditions. The integration of CD and GEM is made possible while significantly simplifying implementation and maintaining comparable performance with existing CD approaches.