Impact of friction and grain shape on the morphology of sheared granular media

The interplay between dilatancy and particle alignment in sheared granular materials composed of non-spherical particles leads to morphological inhomogeneity. Dilatancy, driven by interparticle friction, causes the packing to expand, while particle alignment tends to densify it. We examine the influence of friction, particle aspect ratio, and initial packing conditions on the steady-state particle alignment and packing density. Unlike spherical particles, non-spherical particles with higher AR exhibit either dilatancy or compaction under shear, leading to spontaneous heaping or depression formation. We analyzed the evolution of packing density to identify whether dilatancy or compression prevails within the shear band.