Informatica

The paper describes the development and performance of parallel algorithms for the discrete element method (DEM) software. Spatial domain decomposition strategy and message passing inter-processor communication have been implemented in the DEMMAT code for simulation of visco-elastic frictional granular media. The novel algorithm combining link-cells for contact detection, the static domain decomposition for parallelization and MPI data transfer for processors exchanging particles has been developed for distributed memory PC clusters. The parallel software DEMMAT_PAR has been applied to model compacting of spherical particles in the rectangular box. Two benchmark problems with different numbers of particles have been solved in order to measure parallel efficiency of the code. The inter-processor communication has been examined in order to improve domain decomposition topology and to achieve better load balancing. The speed-up equal to 11 has been obtained on 16 processors. The parallel performance study has been performed on the PC cluster VILKAS of Vilnius Gediminas Technical University, Lithuania.

The paper considers moving locally predefined (MLP) finite element remeshing technique for deep penetration of the rigid cone into homogeneous and porous medium. Remeshing presents a computational tool implemented in the form of postprocessor type software compatible with standard FEM codes. It involves a transfer operation combining both the moving least square method based on stress patch recovery and the interpolation method for transfer of state variables. The developed MLP remeshing is able to overcome numerical difficulties occurring due to large distortions of the Lagrangian mesh and contact sliding and capture steady‐state behavior. It shows good performance in modeling of cone penetration into elasto‐plastic homogeneous and porous media reaching several diameters of the cone.