Simulation of Multi-Axial Compaction of Granular Media from Loose to High Relative Densities

摘要

A Multi-Particle Finite Element Model (MPFEM) was used to explore the densification yield surfaces of a collection of monosize particles in 2-D. Individual particles discretized with a finite element mesh allow for a full description of the contact mechanics and the local and global particle kinematics. Compaction modes ranging from hydrostatic to that of high shear are studied for various levels of interparticle friction. Isodensity curves in stress-space during densification are shown to take the equivalent shape of a cap and cone model whose shear failure line has a slope that is a function of interparticle friction. The combined effect of particle movements with early contact indentation leads to a softer global response to externally applied strains than other analytical or computation models. This work illustrates that the MPFEM model is useful in describing the interparticle behavior and its effect on microscopic and macroscopic response for various strain histories.