Hypoplastic model for solid-like and fluid-like granular flows

Abstract

We present a unified constitutive model for the solid-like and fluid-like behaviour of granular materials by decomposing the stress rate tensor into frictional and collisional parts. An enhancement to the classical hypoplastic model is implemented to consider the acceleration effect in both steady and unsteady granular flows, achieved by introducing a higher-order strain rate. This model can effectively capture the rate-independent and rate-dependent behaviours observed in solid-like and fluid-like granular flows. Performance and validation of the unified model are presented through numerical simulations of diverse element tests.