Failure in granular materials based on acoustic tensor: a numerical analysis

Abstract

We investigate failure in granular material with numerical simulations based upon DEM (Distinct Element Method). Failure is associated with a discontinuity in a component of the incremental strain over a plane surface through the condition of the determinant of the acoustic tensor to be zero. DEM simulations are carried out on an aggregate of elastic frictional spheres, initially isotropically compressed and then sheared at constant pressure. The components of the stiffness tensor are evaluated numerically in stressed states along the triaxial test, and employed in the condition of the acoustic tensor to predict localization. This occurs in the pre-peak region, where the material behavior is on average incrementally frictionless, i.e., change in deviatoric stress due to the tangential forces is negligible.