Elastic energy of a straight dislocation and contribution from core tractions

TL;DR

This paper derives a new expression for the core traction contribution to dislocation elastic energy in anisotropic materials, enabling more accurate calculation of intrinsic dislocation core energies from atomic simulations.

Contribution

It introduces a formalism to include core tractions in elastic energy calculations, making core energies independent of external defects and consistent with Peach-Koehler forces.

Findings

Core energies of dislocations in bcc iron calculated with the new formalism.

Dislocations gliding in {110} planes are more stable than in {112} planes.

The core traction contribution affects the stability analysis of dislocation configurations.

Abstract

We derive an expression of the core traction contribution to the dislocation elastic energy within linear anisotropic elasticity theory using the sextic formalism. With this contribution, the elastic energy is a state variable consistent with the work of the Peach-Koehler forces. This contribution needs also to be considered when extracting from atomic simulations core energies. The core energies thus obtained are real intrinsic dislocation properties: they do not depend on the presence and position of other defects. This is illustrated by calculating core energies of edge dislocation in bcc iron, where we show that dislocations gliding in {110} planes are more stable than those gliding in {112} planes.