Residual Stresses in Glasses

TL;DR

This paper investigates how residual stresses in glasses depend on their formation history, using simulations and theory to connect microscopic dynamics with macroscopic stress relaxation.

Contribution

It introduces a theoretical and simulation-based analysis of residual stress formation and relaxation in glasses, highlighting history dependence and microscopic-macroscopic links.

Findings

Residual stresses relax partially, leaving persistent residual stress.

Relaxation curves scale with shear rate times, even without flow.

Microscopic displacements relate to residual liquefaction length scale.

Abstract

The history dependence of the glasses formed from flow-melted steady states by a sudden cessation of the shear rate $\dot\gamma$ is studied in colloidal suspensions, by molecular dynamics simulations, and mode-coupling theory. In an ideal glass, stresses relax only partially, leaving behind a finite persistent residual stress. For intermediate times, relaxation curves scale as a function of $\dot\gamma t$, even though no flow is present. The macroscopic stress evolution is connected to a length scale of residual liquefaction displayed by microscopic mean-squared displacements. The theory describes this history dependence of glasses sharing the same thermodynamic state variables, but differing static properties.