Modeling of a cohesive granular materials by a multi-scale approach

The paper presents a FEM×DEM two-scale modeling of cohesive granular materials. At the microscopic level, a Discrete Element Method (DEM) is used to model the granular structure (rigid disks). At the macroscopic level, the numerical solution of a boundary value problem is obtained via a Finite Element Method (FEM) formulation. In order to bridge the gap between micro-and macro-scale, the concept of Representative Volume Element (REV) is applied: the average REV stress and the consistent tangent operators are obtained in each macroscopic integration point as the results of DEM simulation. The numerical constitutive law is determined through the DEM modeling of the microstructure to take into account the discrete nature of granular materials. The computational homogenization method is first described and then illustrated in the case of a biaxial compression test.