Directional distortional hardening in metal plasticity within thermodynamics

Heidi P Feigenbaum, Yannis F. Dafalias

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

This paper presents a complete theory for metal plasticity that includes isotropic, kinematic, and directional distortional hardening, within the framework of thermodynamics. Directional distortion is defined here as the formation of a region of high curvature on the yield surface, approximately in the direction of loading, and a region of flattening approximately in the opposite direction, as observed in experiments on various types of metals. The distinguishing features of this theory are the introduction of a fourth order tensor-valued internal variable, whose evolution in conjunction with a directional scalar multiplier describes the evolving directional distortion, and the fact that the hardening laws for all internal variables are derived on the basis of sufficient conditions to satisfy the thermodynamic requirement of positive dissipation. The applicability of the theory is illustrated by fitting experimental data on distorted yield surfaces in the course of plastic deformation.

Original languageEnglish (US)
Pages (from-to)7526-7542
Number of pages17
JournalInternational Journal of Solids and Structures
Volume44
Issue number22-23
DOIs
StatePublished - Nov 2007
Externally publishedYes

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Keywords

  • Distortional hardening
  • Plasticity
  • Thermodynamics

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials

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