Quadric surface approximation of failure criteria for granular materials in plane problem

In this paper, we discuss the failure surface of granular materials based on numerical experiments by a micro-scale analysis. This paper first presents an overview of the global-local numerical method in order to show how the micro-scale problem provides the constitutive relationship. The 3-dimensional numerical experiments to evaluate the failure surface are then carried out. Through the results of these numerical experiments, the macroscopic failure criteria for idealized granular materials are obtained as a quadratic surface approximation.