Thermodynamic analysis of the Livermore molecular-dynamics simulations of dislocation-mediated plasticity

TL;DR

This paper compares large-scale molecular dynamics simulations of dislocation-mediated plasticity with thermodynamic theory, revealing both agreements and inconsistencies in current phenomenological models.

Contribution

It provides a detailed comparison between computational simulations and thermodynamic theory, highlighting areas where traditional models may be inadequate.

Findings

Simulations and theory agree on strain-rate dependent plastic flow.

Both approaches observe a transient stress peak with low initial dislocation density.

Identifies inconsistencies in conventional phenomenological descriptions.

Abstract

Results of recent large-scale molecular dynamics simulations of dislocation-mediated solid plasticity are campared with predictions of the statistical thermodynamic theory of these phenomena. These computational and theoretical analyses are in substantial agreement with each other in both their descriptions of strain-rate dependent steady plastic flow and of a transient stress peak associated with initially small densities of dislocations. The comparisons between the numerical simulations and basic theory reveal inconsistencies in some conventional phenomenological descriptions of solid plasticity.