ABSTRACT: The brittle fracture of rock is a complicated progressive process caused by isolated microstructural changes. Modelling this process in the compressive stress regime is not straightforward, and precise engineering analysis and design therefore remains problematical. A new way of tackling the problem is through the recently developed local degradation approach, which has been developed...

By means of contact dynamics simulations, we investigate a dense packing composed of polyhedral particles under quasistatic shearing. The effect of particle shape is analyzed by comparing the polyhedra packing with a packing of similar characteristics except for the spherical shape of the particles. The polyhedra packing shows higher shear stress and dilatancy but similar stress-dilatancy relat...

We present some experimental and numerical results based on a simple model designed to give an estimate for the width of a shear zone. We conclude that the observed finite size of the shear zone can be associated with the propagation of the force lines inside the medium. The model, based on a simple argument on the force distribution and dilatancy, predicts a width of about ten grain diameters.

A micromechanical study is made of the relationship between interparticle friction coefficient and macroscopic continuum friction and dissipation in idealised granular materials, using Discrete Element Method simulations with varying . As expected, macroscopic friction and dilatancy increase with . Surprisingly, dissipation is present even when or when . Hence, dissipation in idealised granular...