A discrete particle model and numerical modeling of the failure modes of granular materials

Abstract

PurposeTo present a discrete particle model for granular materials.Design/methodology/approachStarting with kinematical analysis of relative movements of two typical circular grains with different radii in contact, both the relative rolling and the relative sliding motion measurements at contact, including translational and angular velocities (displacements) are defined. Both the rolling and sliding friction tangential forces, and the rolling friction resistance moment, which are constitutively related to corresponding relative motion measurements defined, are formulated and integrated into the framework of dynamic model of the discrete element method.FindingsNumerical results demonstrate that the importance of rolling friction resistance, including both rolling friction tangential force and rolling friction resistance moment, in correct simulations of physical behavior in particulate systems; and the capability of the proposed model in simulating the different types of failure modes, such as the landslide (shear bands), the compression cracking and the mud avalanching, in granular materials.Research limitations/implicationsEach grain in the particulate system under consideration is assumed to be rigid and circular. Do not account for the effects of plastic deformation at the contact points.Practical implicationsTo model the failure phenomena of granular materials in geo‐mechanics and geo‐technical engineering problems; and to be a component model in a combined discrete‐continuum macroscopic approach or a two‐scale discrete‐continuum micro‐ macro‐scopic approach to granular media.Originality/valueThis paper develops a new discrete particle model to describe granular media in several branches of engineering such as soil mechanics, power technologies or sintering processes.