Continuum Modeling of Dislocation Plasticity: Theory, Numerical Implementation and Comparison to Discrete Dislocation Simulations

Abstract

The development of advanced materials is driven by continuous progress in the synthesis and control of materials microstructure on sub-micrometer and nanometer scales. Confined to these length-scales, many materials show strikingly different physical properties from their bulk counterparts, like a strong increase in flow stress with decreasing size. This calls for an increased effort on physically motivated continuum theories which can predict size-dependent plasticity by accounting for length scales associated with the dislocation microstructure. An important recent development has been the formulation of a Continuum Dislocation Dynamics (CDD) Theory which provides a kinematically consistent continuum description of the dynamics of curved dislocation systems [1]. Here we present a brief overview of the CDD method and illustrate the implementation of the CDD by numerical examples, the bending of a thin film, the torsion of a wire, and the plastic flow around an elastic inclusion. Results are compared to three-dimensional discrete dislocation dynamics simulations.