The role of irregular particle geometry in highly plastic impact

Abstract

The impact of irregular micro-particles against ductile substrates is ubiquitous in engineering equipment, and predicting their rebound through reduced-order models is often necessary. Poor understanding of how non-spherical geometry influences rebound behavior – especially in the regime of finite plastic deformation of the substrate – greatly limits the utility of existing rebound models. Here, high-fidelity impact simulations are leveraged to extract the key features that emerge from irregular, fully resolved sand particle geometries and to identify the physical mechanisms driving them. We show that energy partitioning throughout the impact process differs fundamentally between the spherical and irregular sand particle geometries considered. Because of its relationship with rotation induced during impact, the normalized moment arm parameterization of global particle mass distribution is found to be highly effective in capturing these differences. Finer details of particle shape governing local contact geometry, e.g., local angularity, are argued to be of secondary importance.