In review of micromechanical laws for granular materials, there is a relationship that describes the stress state, fabric, and contact forces among particles, which is called “Stress-Force-Fabric” (SFF) relationship. SFF relationship can properly describe the media including the anisotropic particles such as polygonal particles, but the particles should be arranged randomly which constitutes isotopic granular media. The question is if this relationship is still true for anisotropic media, in which the elongated particles are arranged directionally. In this paper, reliability of SFF relationship is examined for both isotropic and anisotropic samples. To this aim, Discrete Element Method (DEM) is applied to compare the simulated behavior of isotropic and anisotropic assemblies. The geometry of the particles are considered to be polygonal as well as elongated. The behavior of such samples are studied in terms of stress ratio, which is calculated from macroscopic and microscopic points of view. The results show that the so called SFF can well predict the behavior of isotropic sample but the predictions for anisotropic samples are not acceptable.

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