Fracture of granular materials composed of arbitrary grain shapes: A new cohesive interaction model

TL;DR

This paper introduces a novel discrete element model that simulates cohesive interactions between arbitrarily shaped grains in 2D and 3D, enabling more realistic fracture analysis of granular materials.

Contribution

The model allows for cohesive interactions between particles of any shape, extending beyond simple geometries, and is validated through 2D compression simulations.

Findings

The model reproduces macroscopic behavior of granular aggregates under compression.

It captures fracture initiation and propagation.

Parameter studies inform model's ability to mimic various behaviors.

Abstract

Discrete Element Methods (DEM) are a useful tool to model the fracture of cohesive granular materials. For this kind of application, simple particle shapes (discs in 2D, spheres in 3D) are usually employed. However, dealing with more general particle shapes allows to account for the natural heterogeneity of grains inside real materials. We present a discrete model allowing to mimic cohesion between contacting or non-contacting particles whatever their shape in 2D and 3D. The cohesive interactions are made of cohesion points placed on interacting particles, with the aim of representing a cohesive phase lying between the grains. Contact situations are solved according to unilateral contact and Coulomb friction laws. In order to test the developed model, 2D unixial compression simulations are performed. Numerical results show the ability of the model to mimic the macroscopic behavior of an aggregate grain subject to axial compression, as well as fracture initiation and propagation. A study of the influence of model and sample parameters provides important information on the ability of the model to reproduce various behaviors.