Thermodynamic dislocation theory of adiabatic shear banding in steel

TL;DR

This paper applies a thermodynamic dislocation theory to explain adiabatic shear banding in steel, successfully matching experimental stress-strain data across various temperatures and strain rates using a minimal set of parameters.

Contribution

It introduces a physics-based model that predicts shear banding behavior in steel, incorporating a simple disturbance mechanism to trigger instabilities.

Findings

The model accurately reproduces experimental stress-strain curves.

A small set of parameters suffices to describe behavior across conditions.

The disturbance model explains shear band initiation.

Abstract

The statistical-thermodynamic dislocation theory developed in our earlier studies is used here in an analysis of the experimental observations of adiabatic shear banding in steel by Marchand and Duffy (1988). Employing a small set of physics-based parameters, which we expect to be approximately independent of strain rate and temperature, we are able to explain experimental stress-strain curves at six different temperatures and four different strain rates. We make a simple model of a weak notch-like disturbance that, when driven hard enough, triggers shear banding instabilities that are quantitatively comparable with those seen in the experiments.