Discrete element modelling of the resilient behaviour of unbound granular aggregates

Abstract

The scope of this study is to use a three-dimensional discrete element model to simulate the resilient response of an unbound granular material subjected to sinusoidal loading in a triaxial sample and to compare the simulated results to experimental results. A three-dimensional discrete element model, where each grain interacts with its neighbour grains, allows a micromechanical approach to modelling. By doing the sensitivity analysis on the input parameters the model can be evaluated and insight gained about the factors that affect the resilient behaviour. Uniform spherical grains were used in both the DEM simulations and in the triaxial experiments. Two contact models, linear visco-elastic and Hertzian, and two types of confinement, a uniform cylinder and a flexible membrane, are tested in the simulations. Comparison of the simulation results with the results of similar laboratory experiments shows that the discrete element approach is suitable to model idealised aggregate grains.

Discrete element method simulations of Mars Exploration Rover wheel performance

“…7 with the stress ratio of the best-fit DEM particle bed used in this study. The DEM particle bed stress ratio versus strain curves were obtained by simulating a geotechnical tri-axial strength test cell following the procedure of Uthus et al (2008) and Knuth et al (2012). Data from JSC 1-A are being used in this discussion, as we are unaware of any available stress ratio versus strain data for MMS.…”

Micromechanics of vortices in granular media: connection to shear bands and implications for continuum modelling of failure in geomaterials

“…We begin by giving an overview of the DEM simulations used in this study. We consider two families of DEM simulations developed by various groups and used to study the micromechanical behaviour of cohesionless samples undergoing localised and diffuse failure [9,17,25,27,28,[30][31][32][33][34]. The first are 2D systems comprising spherical particles constrained to the plane and subjected to biaxial compression.…”

Discrete Element Method Simulations of Digging in JSC-1a

“…The scoop model described here is a modest attempt to develop such a relationship. The scoop model together with an existing discrete element based model of a soil triaxial test (Uthus, et al, 2008) give researchers a chance to simulate the behavior of a scoop on model soil and then test the same model soil in a triaxial cell. This procedure may give researchers a framework to better infer lunar soil properties from the in-situ behavior of the scoop.…”