Coarse-graining amorphous plasticity: impact of rejuvenation and disorder

TL;DR

This paper investigates how to effectively coarse-grain amorphous plasticity models from atomistic to mesoscopic scales, emphasizing the roles of disorder and rejuvenation in reproducing key physical behaviors.

Contribution

It introduces a scalar elasto-plastic model incorporating disorder and rejuvenation effects to better capture amorphous plasticity phenomena at larger scales.

Findings

Rejuvenation scenarios reproduce the evolution of local yield stress.

Disorder strength influences localization behavior.

Two key dimensionless parameters govern the model's accuracy.

Abstract

The coarse-graining of amorphous plasticity from the atomistic to the mesoscopic scale is studied in the framework of a simple scalar elasto-plastic model. Building on recent results obtained on the atomistic scale, we discuss the interest in a disordered landscape-informed threshold disorder to reproduce the physics of amorphous plasticity. We show that accounting for a rejuvenation scenario allows us to reproduce quasi-quantitatively the evolution of the mean local yield stress and the localization behavior. We emphasize the crucial role of two dimensionless parameters: the relative strength of the yield stress disorder with respect to the typical stress drops associated with a plastic rearrangement, and the age parameter characterizing the relative stability of the initial glass with respect to the rejuvenated glass that emerges upon shear deformation.