Exploring the effect of particle shape caused by erosion on the shear behaviour of granular materials via the DEM

Abstract

The fragments from crushed rock are initially very angular. The erosion process causes the fragment shape to evolve from angular to well rounded and affects the mechanical behaviour of granular materials. This report explores the effect of particle shape caused by erosion (Er) on macroscopic and microscopic behaviour under triaxial compression tests of granular materials via the discrete element method. A convex rigid block was employed to model particles with different erosion degrees. After being prepared in the densest condition, all particle assemblies were subjected to axial compression until a critical state was reached. The macroscopic characteristics, including the shear strength and dilatancy response, were investigated. As Er increased, the shear strength generally decreased, and the volumetric strain monotonically decreased. Then, the microscopic characteristics, including the coordination number, particle rotation, percentage of sliding contacts and contact force, were examined. Finally, analysis-related anisotropy coefficients of the entire contact network were evaluated to probe the microscopic origins of the peak and residual shear strength related to Er.