DEM simulation of polyhedral particle cracking using a combined Mohr–Coulomb–Weibull failure criterion

Abstract

In this work, at first a new failure criterion for breakage of brittle particle systems is proposed, which combines the classical Mohr–Coulomb strength criterion with the probabilistic Weibull concept. This failure criterion is especially applicable to particle systems under compression load and accounts for the size-dependence of the material’s strength. Second, the Discrete Element Method (DEM) is implemented for sharp edged particles of convex polyhedral shape. The Mohr–Coulomb–Weibull criterion is integrated into the running DEM procedure to simulate progressive particle cracking and comminution of particle systems. The feasibility of the model was tested with simple uniaxial and triaxial compressive loading states, and the influence of relevant material parameters was studied. As a first application example of the method, an oedometric experiment was simulated, whereby coarse quartzite particles are compressed in a piston-die press. The results show good qualitative agreement with the experimentally observed particle size distribution. Thus, the ability of the suggested approach has been proved to reproduce important features as the size effect and the influence of stress state.