On the Bauschinger effect in supercoooled melts under shear: results from mode coupling theory and molecular dynamics simulations

TL;DR

This paper investigates the Bauschinger effect in supercooled melts under shear, combining mode-coupling theory and molecular dynamics simulations to understand history-dependent nonlinear rheology and stress responses.

Contribution

It introduces a combined approach of MCT and molecular dynamics to analyze the Bauschinger effect and nonlinear rheology in supercooled melts under shear.

Findings

Memory effects cause stress-overshoot disappearance.

Stress response depends on shear history.

Single-particle motion relates to macroscopic stress response.

Abstract

We study the nonlinear rheology of a glass-forming binary mixture under the reversal of shear flow using molecular dynamics simulations and a schematic model of the mode-coupling theory of the glass transition (MCT). Memory effects lead to a history-dependent response, as exemplified by the vanishing of a stress-overshoot phenomenon in the stress--strain curves of the sheared liquid, and a change in the apparent elastic coefficients around states with zero stress. We investigate the various retarded contributions to the stress response at a given time schematically within MCT. The connection of this macroscopic response to single-particle motion is demonstrated using molecular-dynamics simulation.