The Effect of Lode Angle and Particle Aspect Ratio on Fabric Evolution in Granular Assemblies: A DEM-CFM Approach

Abstract This study employs Discrete Element Method (DEM) to pursue two primary objectives: firstly, exploring the influence of anisotropy in terms of initial fabric and induced by variations in applied stress on the undrained response of granular assemblies; secondly, investigating the impact of Lode angle ( θ ) and particle Aspect Ratio (AR) on fabric evolution under continuous shearing. To achieve this, soil samples with various initial fabric and elongated particles are simulated. A DEM-Coupled Fluid Method (CFM) is used to account for fluid-solid interactions under undrained multi-dimensional conditions. The simulation results underscore the considerable impact of the Lode angle and particle shape on the stress-strain behavior of granular materials. Additionally, the evolution of fabric is mainly influenced by the stress state and particle AR.