On an efficient hybrid soft and hard sphere collision integration scheme for DEM

This paper introduces a novel hybrid collision integration scheme that combines the benefits of the hard-sphere and the soft-sphere methodology. It assumes that the larger part of the collisions are binary and can be solved in one step. The remainder of the collisions involving more than two particles are handled with a classical soft-sphere scheme. Results for a bounding box problem, employing the classical soft-sphere scheme and the hybrid scheme are compared in terms of energy budget conservation. The hybrid scheme is more accurate and more importantly it is roughly one order of magnitude faster.