A Dual-Level Particle Breakage Model for Irregular Particles in DEM

Particle breakage plays a crucial role in the mechanical behaviour of granular soils. However, existing breakage models in discrete element method (DEM) struggle to accurately represent the breakage process of irregular particles with high computational efficiency. This study proposes a dual-level particle breakage model for irregular particles. At the particle level, the octahedral shear stress serves as the failure criterion, determining whether the particle undergoes breakage. Once the particle level breakage condition is met, sub-particle level failure criteria are applied to identify critical contact points leading to local breakage. The proposed model is validated through comparisons with experimental results including single particle crushing tests and oedometer tests with irregular-shaped particles. In the single particle crushing test simulations, the model successfully reproduces fracture patterns, fragment size distributions, and sequential particle breakage observed in the experiments. When modelling the multi-particle oedometer tests, the model accurately captures the stress-strain response, particle size distribution evolution, and fragment morphologies under a wide range of stress levels. Overall, the proposed method offers a robust and efficient framework for simulating the breakage of irregular-shaped particles, with strong potential for addressing engineering challenges related to particle breakage.