Parallel discrete element simulation of poly-dispersed granular material

The paper presents parallel 3D DEM simulation of poly-dispersed material described by the normal size distribution. Static domain decomposition and message passing inter-processor communication have been implemented in the DEM code. A novel algorithm for moving particles that exchange processors has been incorporated in the domain decomposition framework. Parallel performance of the developed algorithm and software has been investigated by a series of benchmark tests conducting tri-axial compaction of material with different numbers of particles, heterogeneity ratios and compaction durations. The speed-up equal to 8.81 has been obtained on 10 processors of the distributed memory PC cluster. It has been shown that a drastic increase of computational expenses of simulation for the poly-dispersed material in terms of CPU time is associated with the increase of its heterogeneity. A contribution of the temporal evolution of microscopic behaviour has also been illustrated.