Anisotropy of Weakly Vibrated Granular Flows

TL;DR

This study experimentally investigates how the internal fabric anisotropy of weakly vibrated granular flows depends on driving conditions and stresses, revealing its critical role in flow rheology.

Contribution

It demonstrates the dependence of granular fabric anisotropy on driving parameters and stresses, establishing a direct link between stresses and anisotropy in granular flows.

Findings

Anisotropy varies with flow rate and vibration strength.

Anisotropy collapses when plotted against driving stresses.

Small anisotropies correspond to vanishing shear stresses.

Abstract

We experimentally probe the anisotropy of the fabric of weakly vibrated, flowing granular media. Depending on the driving parameters --- flow rate and vibration strength --- this anisotropy varies significantly. We show how the anisotropy collapses when plotted as function of the driving stresses, uncovering a direct link between stresses and anisotropy. Moreover, our data suggests that for small anisotropies, the shear stresses vanish. Anisotropy of the fabric of granular media thus plays a crucial role in determining the rheology of granular flows.