DEM Analysis on Drained and Undrained Fabric Evolution under Cyclic Loading

Abstract The significant role of fabric evolution of granular materials under monotonic loading until the critical state has been highlighted in the literature. On the contrary, its role under cyclic loading has received less scrutiny. Hence, this study employs the Discrete Element Method (DEM) in 2 dimensions to investigate fabric evolution of granular materials under constant mean stress (drained) and constant volume (undrained) cyclic loading. The analysis focuses on fabric evolution by analyzing stress-strain responses and a directional fabric norm based on contact normal vectors. Results reveal distinct fabric responses for the two loading conditions, with the fabric norm showing periodic variations with increasing peak fabric norm values in constant volume loading and more consistent behavior in constant mean stress loading.