Random packing of tetrahedral particles using the polyhedral discrete element method

The random packing of tetrahedral particles is studied by applying the discrete element method (DEM), which simulates the effects of friction, height ratio, and eccentricity. The model predictions are analyzed in terms of packing density and coordination number (CN). It is demonstrated that friction has the maximal effect on packing density and mean CN among the three parameters. The packing density of the regular tetrahedron is 0.71 when extrapolated to a zero friction effect. The shape effects of height ratio and eccentricity show that the regular tetrahedron has the highest packing density in the family of tetrahedra, which is consistent with what has been reported in the literature. Compared with geometry-based packing algorithms, the DEM packing density is much lower. This demonstrates that the inter-particle mechanical forces have a considerable effect on packing. The DEM results agree with the published experimental results, indicating that the polyhedral DEM model is suitable for simulating the random packing of tetrahedral particles.