A Fast Discrete Element Method for Adhesive Particles

Abstract

A 3D JKR-based discrete element method (DEM) is employed to investigate the oblique collisions of micron-sized particles. The energy dissipation pathways are analyzed and the effect of particle size, and impact angles on the critical sticking velocity is discussed. An explicit formula is put forward as a sticking/rebound criterion for collisions of micron-sized particles covering different impact angles, particle sizes, and size ratios. We then propose a fast DEM based on scaling laws to reduce particle Young’s modulus, surface energy and to modify rolling and sliding resistances simultaneously. A novel inversion method is then presented to help users quickly determine the damping coefficient, particle stiffness, and surface energy to reproduce a prescribed experimental result. After validating this inversion method, we apply the fast adhesive DEM to packing problems of microparticles. Measures of the packing fraction, averaged coordination number, and distributions of local packing fraction and contact number of each particle are in good agreement with results simulated using the original value of particle properties. The new method should be helpful to accelerate DEM simulations for systems associated with aggregates or agglomerates.