Micromechanical investigation of particle breakage behavior in confined compression tests

Abstract

This paper aims to give a micromechanical investigation into the progressive size reduction mechanism and its effects on macro responses of granular assemblies during confined compression tests. A series of numerical studies based on the cohesive zone model are presented, incorporating internal deformation and fragmentation behaviors, and the variations of feed profiles are considered. Simulation results reasonably reproduce experimental observations in terms of macro compression responses and typical particle breakage modes. A scaling method is proposed for considering the contributions of fine products. With this method, the fragment size distribution is refined and compare favorably with physical results. The breakage degree is found to be dependent on input energy, regardless of variations of feed profiles including material heterogeneity, gradations, or friction conditions. Furthermore, a quantitative micro-analysis of normalized and cumulative normal contact force distribution, as well as contact orientation distribution is presented in this study, demonstrating the different roles of fragmentation in micro-mechanical response of particle assemblies owing to different materials or boundary friction effects.