Discrete element model for brittle materials

Abstract

We adopt the discrete element method (DEM) to study the fracture behavior of brittle materials. We propose an approach which relates crack initiation to crack growth. The material consists of a set of particles in contact, which allows us to derive an expression for the stress intensity factor as a function of the contact forces and displacements. A classical failure criterion, based on the material’s toughness, is then adopted for the analysis of crack propagation, represented by the loss of cohesion forces between particles. Afterwards, we apply our discrete criterion to uncracked materials under homogenous stress conditions, obtaining a Rankine like behavior. The work results in a simple discrete model which is totally compatible to continuum mechanics, where no calibration tests are required, in contrast to most of discrete approaches.