DEM-XFEM Study of Particle Shape Effect on Particle Breakage of Granular Materials

A numerical approach based on the combination of DEM and XFEM methodologies is adopted to simulate assemblies of various types of breakable angular particles under direct shear loading in order to study the influence particle shape and assembly confinement on the mechanical behavior of granular materials, especially the occurrence of particle breakage. To do so, a number of breakage-disabled (BD) and breakage-enabled (BE) samples were modeled and compared from different macro- and microstructural perspectives. In this approach, the Discrete Element Method (DEM) is used to simulate direct shear tests on particle assemblies, and the eXtended Finite Element Method (XFEM) models the process of particle breakage in any single particle. It is shown that the angularity, eccentricity, and initial orientation of particles significantly affect the particle breakage and mechanical behavior of rockfills.