Simulation of Shear Bands in Granular Material Using Weak Discontinuities in a Hypoplastic Constitutive Model

Abstract

The paper presents the simulation of the creation of shear bands in granular soils by using the concept of weak discontinuities in fracture mechanics. As a result, a hypoplastic constitutive model was extended to capture the additional strain on the shear band. Once extended, the model was implemented in a user subroutine (UMAT) for ABAQUS. Soil behavior before and after the localization of the deformation is separated through the bifurcation criterion. The article presents the results of the element test simulations using the extended hypoplastic model and the Incremental Driver program developed by Niemunis (2007). The results of these simulations are compared to simulations performed with the reference hypoplastic model. These comparisons led to the conclusion that the extended hypoplastic constitutive model reproduces in a realistic and simple way the formation of shear bands in granular media