Exploring the role of particle-form polydispersity in the fabric of granular packing: Insights from DEM simulations with ellipsoidal particle assemblies

Granular materials, such as sand, exhibit a wide range of particle sizes and shapes, known as polydispersity. This study aims to investigate the effects of particle-form (first-level approximation of particle shape) polydispersity on a fabric of granular packing using DEM simulations of ellipsoidal particle assemblies. A framework for DEM simulations is proposed to investigate the particle-form polydispersity, and an overall polydispersity index (OPI) is introduced to quantify its magnitude. Various parameters are employed to quantify the fabric, including packing density, coordination number, contact force, and fabric anisotropy. The results highlight that the particle-form polydispersity notably affects the packing density and mean coordination number of the granular packings. Furthermore, a prediction model for the packing density and mean coordination number of polydisperse packings is proposed based on the correlations fitted from the monodisperse packing data.