Discrete element simulations of dense packings and heaps made of sphericaland non-spherical particles

The discrete element method (DEM) in the simulation of static packings allo ws one to investigate the behavior of granular materials by modeling the fo rces on the particle level. No macroscopic parameters like the angle of rep ose enter the simulation, but they can be extracted as a result of the part icle properties like friction, roughness or shape. One of the issues of sta tic packings recently discussed is the stress distribution under granular h eaps. This problem is used to highlight the possibilities of modeling at th e particle level using DEM. Phenomena like arching or stress-chains are obs erved even for spherical particles in a regular pile in the absence of fric tion if the bottom is rough. The situation does not change much if polygona l, frictional particles are used without disturbing the regular piling. For more realistic situations, when the pile is built by pouring grains from a bove, the packing and the stresses are influenced by the creation history. The more eccentric the polygons are, the more pronounced a dip is observed in the vertical stress under the apex of the sand-pile. (C) 2000 Elsevier S cience S.A. All rights reserved.