A simple micro-inspired model for granular materials made of hollow crushable particles

This paper presents a new macroscopic constitutive model for granular materials constituted by hollow, crushable particles. Inspired by micromechanical data, the model extends the Sinfonietta-Classica elastoplastic model to incorporate particle breakage and the resulting compaction. The behaviour of the material is characterised by three distinct regimes: initial rigidity, high compressibility due to particle crushing, and subsequent post-breakage sti↵ening. The model relies on a relationship between volumetric strain and the fraction of broken particles, captured by a microscopically informed smoothed transition function. A numerical simulation under oedometric conditions is carried out to validate the model, to evaluate its ability to reproduce discrete element method (DEM) results. The proposed approach allows for the derivation of new parameters using DEM simulations, while classical parameters can be determined through standard tests on the fully crushed material. Future work aims to generalize the model to account for finite deformation, diverse loading paths, and compaction bands formation.