Shear jamming and fragility of suspensions in a continuum model with elastic constraints

TL;DR

This paper presents a tensorial continuum model that explains shear jamming and fragility in suspensions by linking elastic microstructural response to shear behavior, rather than viscosity divergence.

Contribution

It introduces a novel continuum model capturing shear jamming and reversibility in suspensions through elastic constraints, advancing understanding of suspension mechanics.

Findings

The model reproduces shear jamming and unjamming under traction inversion.

Shear jamming is linked to elastic microstructure response, not viscosity divergence.

The model is validated in paradigmatic geometries.

Abstract

Under an applied traction, highly concentrated suspensions of solid particles in fluids can turn from a state in which they flow to a state in which they counteract the traction as an elastic solid: a shear-jammed state. Remarkably, the suspension can turn back to the flowing state simply by inverting the traction. A tensorial model is presented and tested in paradigmatic cases. We show that, to reproduce the phenomenology of shear jamming in generic geometries, it is necessary to link this effect to the elastic response supported by the suspension microstructure rather than to a divergence of the viscosity.