Computer simulation of three dimensional shearing of granular materials: Formation of shear bands

TL;DR

This paper uses 3D computer simulations with the Distinct Element Method to study how shear bands form in granular materials during triaxial shear tests, reproducing experimental observations and analyzing the formation mechanisms.

Contribution

It demonstrates the formation of shear bands in granular materials through detailed 3D DEM simulations, aligning with experimental results and providing insights into the formation mechanisms.

Findings

Shear bands observed in simulations match experimental morphologies.

Stress-strain relations in simulations agree with experimental data.

Different shear band morphologies can be reproduced in the model.

Abstract

We used computer simulations to study spontaneous strain localization in granular materials, as a result of symmetry breaking non-homogeneous deformations. Axisymmetric triaxial shear tests were simulated by means of standard three-dimensional Distinct Element Method (DEM) with spherical grains. Carefully prepared dense specimens were compressed between two platens and, in order to mimic the experimental conditions, stress controlled, (initially) axisymmetric boundary conditions were constructed. Strain localization gave rise to visible shear bands, previously found experimentally under similar conditions by several groups, and different morphologies could be reproduced. We examined the stress-strain relation during the process and found good agreement with experiments. Formation mechanism of shear bands is discussed.