Influence of Particle Shape on Microstructure of Granular Materials under Gravity

Abstract

The paper presents a study of particle shape effect on microstructure within granular materials in gravitational environments using samples acquired from three-dimensional (3D) discrete element method (DEM) modeling and simulation (M&S) of gravitational pluviations. Three-axis ellipsoidal particles with various aspect ratios are examined for their spatial orientations, and the three-axis probability density functions (PDF) are analyzed before and after pluviation. A complicated data structure, convex hull, is employed to construct tetrahedra that connect particle centroids and investigate the internal topology and fabric of particle assemblies composed of various particle shapes. The Qhull-constructed connected tetrahedra within granular materials may serve as a useful tool to study the geometrical fabric (such as tetrahedron shape, solid angles, and void ratio), investigate particle collision requirements in sample preparation, describe strain/deformation/failure mechanisms, and explore stress distribution over granular materials.