Dynamical yield criterion for granular matter from first principles

TL;DR

This paper develops a first-principles model to derive an analytical dynamical yield surface for dense granular matter, bridging behaviors of soft and hard materials and emphasizing the role of effective friction at yielding.

Contribution

It introduces a novel analytical model predicting the dynamical yield surface for granular matter from liquid state theory, unifying failure behaviors of different material types.

Findings

Derived an analytical equation for the yield surface.

Showed the yield surface interpolates between soft and hard material failure.

Highlighted the importance of the effective friction coefficient at yielding.

Abstract

We investigate, using a recently developed model of liquid state theory describing the rheology of dense granular flows, how a yield stress appears in granular matter at the yielding transition. Our model allows us to predict an analytical equation of the corresponding dynamical yield surface, which is compared to usual models of solid fracture. In particular, this yield surface interpolates between the typical failure behaviors of soft and hard materials. This work also underlines the central role played by the effective friction coefficient at the yielding transition.