Study on the effect of grain morphology on shear strength in granular materials via GPU based discrete element method simulations

The majority of publications in DEM use simplified particle shapes, in this study we use polyhedral shapes to determine the effect of particle shape on shear strength via a direct-shear test. Grain aspect ratio was found to be the primary determinant of shear strength with elongated polyhedra having a lower shear resistance. Grain irregularity also had a significant effect, shapes with isotropic contacts angles had the highest shear strength. The variability of granular material behavior due to shape was demonstrated by non-convex shapes re-orientating to jam in certain cases. Shapes with multi-stable packed orientations were found to offer the highest resistance to reordering under localized vibration.