Development of mean-field continuum dislocation kinematics with junction reactions using de Rham currents and graph theory

Kyle Starkey*, Thomas Hochrainer, Anter El-Azab

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

An accurate description of the evolution of dislocation networks is an essential part of discrete and continuum dislocation dynamics models. These networks evolve by motion of the dislocation lines and by forming junctions between these lines via cross slip, annihilation and junction reactions. In this work, we introduce these dislocation reactions into continuum dislocation models using the theory of de Rham currents. We introduce dislocations on each slip system as potentially open lines whose boundaries are associated with junction points and, therefore, still create a network of collectively closed lines that satisfy the classical relations α=curlβp and divα=0 for the dislocation density tensor α and the plastic distortion βp. To ensure this, we leverage Frank's second rule at the junction nodes and the concept of virtual dislocation segments. We introduce the junction point density as a new state variable that represents the distribution of junction points within the crystal containing the dislocation network. Adding this information requires knowledge of the global structure of the dislocation network, which we obtain from its representation as a graph. We derive transport relations for the dislocation line density on each slip system in the crystal, which now includes a term that corresponds to the motion of junction points. We also derive the transport relations for junction points, which include source terms that reflect the topology changes of the dislocation network due to junction formation.

Original languageEnglish
Article number104685
JournalJournal of the Mechanics and Physics of Solids
Volume158
DOIs
Publication statusPublished - Jan 2022

Keywords

  • Continuum dislocation dynamics
  • de Rham currents
  • Dislocation reactions
  • Graph theory

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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