DEM Simulation of Micro-Macro Mechanical Behaviour of Granular Materials

Abstract

The mechanical responses of granular materials are affected significantly by the properties of the individual particle. In order to establish the link between the micro and macro parameters, series of numerical biaxial simulations are carried out using two-dimensional discrete element method. The microscale mechanisms of mechanical behavior of granular materials are investigated through sensitivity analyses. The key influence of microscale parameters on the strength and deformation are discussed respectively. The peak strength depends on void ratio, friction coefficient and confining stress significantly. The elastic modulus is affected by friction coefficient, confining pressure and stiffness ratio, especially when the friction coefficient ranges from 0.1 to 0.3. The samples with different initial void ratio under the same loading condition can finally achieve the same critical state; the critical states at micro and macro scale are both independent of the initial void ratio.