A Particle Shape Classification Strategy to Inform the Generation of Representative Element Volumes in the Discrete Element Method

Abstract Granular soils feature a wide variety of particle sizes and shapes which makes their discrete simulation a laborious task, as the question arises of what particle shapes should be used to model a real geomaterial. This study introduces a method to generate simplified Representative Element Volumes (REVs) of non-spherical particles in the Discrete Element Method (DEM) with reduced particle shape polydispersity, which nevertheless still represent adequately the shear strength of the real material. A recently-proposed shape classification system is employed to categorise real particles as flat, compact, bladed and elongated, which is based on new definitions of particle flatness and elongation, and representative particles of each shape type are identified. It is shown that REVs of railway ballast with simplified representation of shape polydispersity can adequately represent the shear strength of the real material under triaxial compression, as long as the statistical distribution of flat, compact, bladed and elongated particles is in proportion to that of the real material.