Shear banding, aging and noise dynamics in soft glassy materials

TL;DR

This paper extends the soft glassy rheology model to incorporate noise generated by yield events, successfully explaining viscosity bifurcation, shear banding, and strain-rate hysteresis in soft glassy materials.

Contribution

The extended model introduces a feedback mechanism where yield events generate noise, providing a better understanding of complex flow behaviors in soft glassy materials.

Findings

The model explains viscosity bifurcation phenomena.

It accounts for shear banding observed in experiments.

It sheds light on strain-rate hysteresis in glassy polymers.

Abstract

The `soft glassy rheology' (SGR) model gives an appealing account of the flow of nonergodic soft materials in terms of the local yield dynamics of mesoscopic elements. Newtonian, power-law, and yield-stress fluid regimes arise on varying a `noise temperature', x. Here we extend the model, to capture the idea that the noise is largely caused by yield itself. The extended model can account for the viscosity-bifurcation and shear-banding effects reported recently in a wide range of soft materials. A variant model may shed light on shear banding and strain-rate hysteresis seen in glassy star polymer solutions.