A uniquely defined multiplicative elasto-plasticity model with orthotropic yield function and plastic spin

Manfred Hannes Ulz*, Christian Celigoj

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A rate-independent model for isotropic elastic–orthotropic plastic material behaviour including the plastic spin is presented in this paper. The plastic spin, as introduced by Dafalias, is the spin of the continuum relative to the material substructure. The model is based on a specific multiplicative decomposition of the deformation gradient tensor, which introduces a uniquely defined intermediate configuration as motivated by Casey. We focus our attention on metal sheets in forming processes, in which pre-existing preferred orientations govern the orthotropic plastic behaviour. As a result, we advocate a Hill-type yield criterion enriched by the notion of plastic spin to describe this material behaviour. Our formulation yields three key findings: firstly, the uniquely defined intermediate configuration, namely a plastically stretched intermediate configuration, allows for a neat implementation of the plastic spin; secondly, the algorithmic formulation is straightforward and shows no additional difficulties in the implementation; and thirdly, a good agreement of our numerical model with experimental and numerical results from in-plane sheet forming processes reported in the literature is achieved.

Original languageEnglish
Article number113565
JournalComputer Methods in Applied Mechanics and Engineering
Publication statusPublished - 30 Nov 2020


  • Multiplicative plasticity
  • Orientational evolution
  • Orthotropy
  • Plastic spin
  • Unique intermediate configuration

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Physics and Astronomy(all)
  • Computer Science Applications
  • Computational Mechanics

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