Macro-Micro Responses of Granular Materials under Different b Values Using DEM: Fid-Bau Portal

Macro-Micro Responses of Granular Materials under Different b Values Using DEM

Mahmud Sazzad, Md. / Suzuki, Kiichi / Modaressi-Farahmand-Razavi, A.

Abstract

Granular materials, such as sand, experience different stress paths in nature; and the behavior of granular materials depends on stress conditions. This paper presents a study of the relationship between the macro- and microscale responses of granular materials using the discrete element method (DEM) under general three-dimensional stress conditions specified by the parameter $b$ , which describes the relative magnitude of the intermediate principal stress with respect to the major and minor principal stresses. With this view, a cubical numerical sample consisting of 8,000 spheres was prepared. Six true triaxial tests were conducted with the same numerical sample with no bias in the initial fabric. Different macroscopic results, including the relationship between principal strains, principal deviatoric strains, the evolution of stress and strain increment vectors, and the behavior of strain increment vectors on the $π$ -plane, are discussed. Good consistency between the numerical and experimental results was found. In addition, the macroscale stress ratio correlated with material fabric evolution, which was quantified using a fabric tensor and a unique relationship, was noticed regardless of $b$ value considering the strong contact networks.