Constitutive modeling of superplastic deformation. Part I: Theory and experiments

M. K. Khraisheh, H. M. Zbib, C. H. Hamilton, A. E. Bayoumi

Research output: Contribution to journalArticle

59 Citations (Scopus)


In this work, we investigate the mechanical behavior of superplastic materials under various loading conditions and examine the nature of anisotropy. This and other phenomena are modeled within a continuum theory of viscoplasticity which includes an overstress function, 'yield surface' and internal variables. Anisotropic hardening is represented by an internal stress tensor whose evolution (including plastic spin) consists of hardening, dynamic recovery, and static recovery terms. The 'dynamic' yield surface (within a viscoplasticity formulation) is assumed to be isotropic and depends on both J2 and J3. Various experiments on a Pb-Sn superplastic alloy including tension, jump test, stress relaxation, fixed-end torsion, and combined tension-torsion -tests were performed and the results are used to calibrate and verify the theoretical model. It is shown that the isotropic dynamic surface can successfully model the uniaxial behavior of super-plastic deformation, including stress relaxation, and produces axial stresses in fixed-end torsion.

Original languageEnglish
Pages (from-to)143-164
Number of pages22
JournalInternational Journal of Plasticity
Issue number1-2
Publication statusPublished - 1 Jan 1997


ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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