Efficient Voronoi volume estimation for DEM simulations of granular materials under confined conditions

When the discrete element method (DEM) is used to simulate confined compression of granular materials, the need arises to estimate the void space surrounding each particle with Voronoi polyhedra. This entails recurring Voronoi tessellation with small changes in the geometry, resulting in a considerable computational overhead. To overcome this limitation, we propose a method with the following features: A local determination of the polyhedron volume is used, which considerably simplifies implementation of the method. A linear approximation of the polyhedron volume is utilised, with intermittent exact volume calculations when needed. The method allows highly accurate volume estimates to be obtained at a considerably reduced computational cost. (C) 2015 The Author. Published by Elsevier B.V.