Plane-strain discrete dislocation plasticity incorporating anisotropic elasticity

Siamak Soleymani Shishvan, Soheil Mohammadi, Mohammad Rahimian, Erik Van der Giessen*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

27 Citations (Scopus)
30 Downloads (Pure)

Abstract

The increasing application of plane-strain testing at the (sub-) micron length scale of materials that comprise elastically anisotropic cubic crystals has motivated the development of an anisotropic two-dimensional discrete dislocation plasticity (2D DDP) method. The method relies on the observation that plane-strain plastic deformation of cubic crystals is possible in specific orientations when described in terms of edge dislocations on three effective slip systems. The displacement and stress fields of such dislocations in an unbounded anisotropic crystal are recapitulated, and we propose modified constitutive rules for the discrete dislocation dynamics of anisotropic single crystals. Subsequently, to handle polycrystalline problems, we follow an idea of O'Day and Curtin (J. Appl. Mech. 71 (2004) 805-815) and treat each grain as a plastic domain, and adopt superposition to determine the overall response. This method allows for a computationally efficient analysis of micro-scale size effects. As an application, we study freestanding thin copper films under plane-strain tension. First, the computational framework is validated for the special case of isotropic thin films modeled by means of a standard 2D DDP method. Next, predictions of size dependent plastic behavior in anisotropic columnar-grained thin films with varying thickness/grain size are presented and compared with the isotropic results. (C) 2010 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)374-387
Number of pages14
JournalInternational Journal of Solids and Structures
Volume48
Issue number2
DOIs
Publication statusPublished - 15-Jan-2011

Keywords

  • Discrete dislocation plasticity (DDP)
  • Anisotropic elasticity
  • Size effects
  • Thin films
  • FREESTANDING THIN-FILMS
  • CRYSTAL PLASTICITY
  • SINGLE-CRYSTAL
  • SUBMICRON INDENTATION
  • GRADIENT THEORY
  • YIELD STRENGTH
  • BAUSCHINGER
  • DEFORMATION
  • PREDICTIONS
  • DYNAMICS

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