Investigation of fabric evolution in elliptical granular materials for kinematic models using the Discrete Element Method

摘要

This paper presents investigation on the evolutions of different fabrics under simple shear tests by the Discrete Element Method (DEM) and aims to find a simple and suitable fabric rate to represent an angular velocity variable v in kinematic models for non-coaxial granular materials. Strain-rate controlled undrained DEM monotonic and cyclic simple shear tests were carried out on inherent anisotropy elliptical granular materials with the aspect ratios of 1.4 and 1.7. Two fabric rates, which are based on contact normal and contact force fabrics were considered. The authors compared the theoretical rates and the two fabric rates for the medium-dense specimen and their respective average values for loose, medium-dense and dense specimens. The evaluation demonstrates that the variable v can not be represented by the deviator fabric rates of contact normal and contact force following Rothenburg's fabric definition.