Abstract
We study the rheology of dense granular flows for frictionless spherocylinders by means of 3D numerical simulations. As in the case of spherical particles, the effective friction is an increasing function of the inertial number , and we systematically investigate the dependence of on the particle aspect ratio , as well as that of the normal stress differences, the volume fraction, and the coordination number. We show in particular that the quasistatic friction coefficient is nonmonotonic with : from the spherical case , it first sharply increases, reaches a maximum around , and then gently decreases until , passing its initial value at . We provide a microscopic interpretation for this unexpected behavior through the analysis of the distribution of dissipative contacts around the particles: as compared to spheres, slightly elongated grains enhance contacts in their central cylindrical band, whereas at larger aspect ratios particles tend to align and dissipate by preferential contacts at their hemispherical caps.
- Received 16 June 2017
DOI:https://doi.org/10.1103/PhysRevE.96.062903
©2017 American Physical Society