INVESTIGATION OF MICROMECHANICAL FEATURES OF IDEALIZED GRANULAR ASSEMBLIES USING DEM

The development of physically‐correct models of granular behaviour under shear deformations must recognize the discrete nature of the medium and the mechanical properties of the constituent grains at the particle level. Numerical simulation of idealized granular materials offers the researcher the possibility of recovering complete information on these systems that can then guide the development of micromechanical‐based models of granular systems. A numerical technique that has proved useful in meeting this goal is the discrete element method (DEM). The computer implementation of this method to observe microfeatures of idealized granular assemblies was first reported in the published literature by Cundall and Strack. Since that time a number of researchers have used the technique to explore the behaviour of idealized granular systems comprising cohesionless assemblies of discs and assemblies of discs comprising indestructible (bonded) contacts. The paper reviews some of the numerical simulation work that has been carried out by the authors to verify stress‐force‐fabric relationships first proposed by Rothenburg and constitutive stress‐strain laws for dense isotropic assemblies of bonded discs. The numerical technique in each case is the same and involves the solution of the equations of motion of each particle using an explicit time/finite difference algorithm which is the essential feature of the DEM.