Thermodynamic dislocation theory: Application to bcc-crystals

TL;DR

This paper refines the thermodynamic dislocation theory and demonstrates its ability to accurately model the stress-strain behavior of various bcc crystals across diverse conditions using a minimal set of parameters.

Contribution

It introduces modifications to the existing dislocation theory and validates it against experimental data for multiple bcc metals with a unified parameter set.

Findings

Accurately fits stress-strain curves of bcc crystals

Works across wide temperature and strain rate ranges

Uses minimal physics-based parameters

Abstract

This paper presents the thermodynamic dislocation theory containing several modifications over its first version which was originally proposed by Langer, Bouchbinder, and Lookman (2010). Employing a small set of physics-based material parameters identified by the large scale least squares analysis, we show that the theory can fit the stress-strain curves of bcc crystals niobium, tantalum, tungsten, and vanadium over a wide range of temperatures and strain rates.