Jamming, Yielding and Rheology of Weakly Vibrated Granular Media

TL;DR

This paper investigates the rheological behavior of dry granular media, revealing non-monotonic flow curves that lead to hysteresis and yielding phenomena, influenced by external vibrations and observed across various geometries and materials.

Contribution

It demonstrates the existence of non-monotonic flow curves in granular media and links them to hysteresis and yielding, across different experimental setups and materials.

Findings

Non-monotonic flow curves cause hysteresis in granular flows.

Weak vibrations influence the flow transition between slow and inertial regimes.

Non-monotonic behavior is consistent across multiple geometries and materials.

Abstract

We establish that the rheological curve of dry granular media is non-monotonic, both in the presence and absence of external mechanical agitations. In the presence of weak vibrations, the non-monotonic flow curves govern a hysteretic transition between slow but steady and fast, inertial flows. In the absence of vibrations, the non-monotonic flow curve governs the yielding behavior of granular media. Finally, we show that non-monotonic flow curves can be seen in at least two different flow geometries and for several granular materials.