Thermodynamic dislocation theory: Bauschinger effect

TL;DR

This paper applies thermodynamic dislocation theory to simulate the Bauschinger effect, demonstrating how back stress influences dislocation behavior and stress response during load reversal in crystals.

Contribution

It introduces a thermodynamic dislocation model to explain the Bauschinger effect in non-uniform plastic deformation under load reversal.

Findings

Back stress reduces shear stress needed for dislocation reversal

Excess dislocations meet and annihilate at the center

Model successfully reproduces the Bauschinger effect

Abstract

The thermodynamic dislocation theory developed for non-uniform plastic deformations is used here to simulate the stress-strain curves for crystals subjected to anti-plane shear-controlled load reversal. We show that the presence of the positive back stress during the load reversal reduces the magnitude of shear stress required to pull excess dislocations back to the center of the specimen. There, the excess dislocations of opposite signs meet and annihilate each other leading to the Bauschinger effect.