Numerical investigation of impact breakage mechanisms of two spherical particles

Abstract

Recently developed peridynamic (PD) simulations, allowing spontaneous crack nucleation and propagation, have been conducted to investigate the dynamic breakage behavior of impact spherical particles as a function of impact speeds. With the increase of impact speed, the Hertzian cracks, primary meridian cracks, secondary meridian cracks, circumferential cracks, and crack bifurcations are observed. The crack propagation speeds can reach 62% Rayleigh wave speed at impact speed of 20 m/s. Then with the further increase of impact speed, crack bifurcation is observed due to dynamic path instability, leading to the catastrophic failure of impact spheres. The evolution of damage ratio, defined as the ratio of broken bonds to total initial bonds in PD model, agrees with previous results using discrete element method (DEM), validating the current model. Furthermore, the comparison between computed and theoretic contact force is performed along with experimental measurements. The research provides additional insights into breakage mechanisms of particles.