A coarse-grained phase-field crystal model of plastic motion

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Marco Salvalaglio - , TUD Dresden University of Technology, City University of Hong Kong (Author)
  • Luiza Angheluta - , University of Oslo (Author)
  • Zhi-Feng Huang - , Wayne State University (Author)
  • Axel Voigt - , TUD Dresden University of Technology (Author)
  • Ken R. Elder - , Oakland University (Author)
  • Jorge Vinals - , University of Minnesota System (Author)

Abstract

The phase-field crystal model in an amplitude equation approximation is shown to provide an accurate description of the deformation field in defected crystalline structures, as well as of dislocation motion. We analyze in detail stress regularization at a dislocation core given by the model, and show how the Burgers vector density can be directly computed from the topological singularities of the phase-field amplitudes. Distortions arising from these amplitudes are then supplemented with non-singular displacements to enforce mechanical equilibrium. This allows for a consistent separation of plastic and elastic time scales in this framework. A finite element method is introduced to solve the combined amplitude and elasticity equations, which is applied to a few prototypical configurations in two spatial dimensions for a crystal of triangular lattice symmetry: i) the stress field induced by an edge dislocation with an analysis of how the amplitude equation regularizes stresses near the dislocation core, ii) the motion of a dislocation dipole as a result of its internal interaction, and iii) the shrinkage of a rotated grain. We compare our results with those given by other extensions of classical elasticity theory, such as strain-gradient elasticity and methods based on the smoothing of Burgers vector densities near defect cores. (C) 2019 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Article number103856
Number of pages14
JournalJournal of the Mechanics and Physics of Solids
Volume137
Publication statusPublished - Apr 2020
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 85077304464
ORCID /0000-0002-4217-0951/work/142237401

Keywords

Keywords

  • phase-field crystal, coarse-graining, crystal plasticity, dislocation motion, finite element method, DISLOCATION DYNAMICS, DISCLINATIONS, SIZE