DEM simulation of particle crushing in a triaxial test considering the influence of particle morphology and coordination number

Abstract

This paper aims to simulate the particle crushing events occurring in the triaxial test considering the irregularity of particles and the coordination number using the three dimensional discrete element method (DEM). Firstly, based on the published micro computed tomography data, the irregular particle shapes were reproduced using the spherical harmonic analysis. The flexible membrane in the triaxial test was modelled using the structural shell elements in FLAC3D. Secondly, a particle crushing criterion based on the maximum interparticle contact force was adopted to predict any particle crushing event. Next, the fragments were generated based on a specific fragmentation pattern once the maximum contact force of a particle satisfies the crushing criterion. This fragmentation pattern depends on the coordination number of the crushed particle and is used to determine the fragment number and volumes. Finally, the particle crushing events were successfully modelled by replacing the crushed particle with the generated fragments with a consideration of the mass conservation. Given the absence of any approach for reproducing the realistic fragmentation pattern of sand particles while maintaining the mass conservation in the existing DEM studies, this paper makes a salient contribution to the DEM modelling of real particle crushing behavior of sands.