On Stress-State Dependent Plasticity Modeling: Significance of the Hydrostatic Stress, the Third Invariant of Stress Deviator and the Non-Associated Flow Rule

Abstract

It has been shown that the plastic response of many materials, including some metallic alloys, depends on the stress state. In this paper, we describe a plasticity model for isotropic materials, which is a function of the hydrostatic stress as well as the second and third invariants of the stress deviator, and present its finite element implementation, including integration of the constitutive equations using the backward Euler method and formulation of the consistent tangent moduli. Special attention is paid for the adoption of the non-associated flow rule. As an application, this model is calibrated and verified for a 5083 aluminum alloy. Furthermore, the Gurson-Tvergaard-Needleman porous plasticity model, which is widely used to simulate the void growth process of ductile fracture, is extended to include the effects of hydrostatic stress and the third invariant of stress deviator on the matrix material.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2010
Accession Number
ADA520876

Entities

People

  • Charles Roe
  • Jun Zhou
  • Matthew Hayden
  • Stephen M. Graham
  • Tingting Zhang
  • Xiaosheng Gao

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aluminum Alloys
  • Constitutive Equations
  • Elastic Properties
  • Equations
  • Hardening
  • Materials
  • Measurement
  • Mechanical Engineering
  • Mechanical Properties
  • Mechanics
  • Plastic Deformation
  • Plastic Flow
  • Plastic Properties
  • Porous Materials
  • Sheet Metal
  • Strain Rate
  • United States Naval Academy

Readers

  • Brain and Cognitive Science; Experimental Psychology; Cognitive Neuroscience
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Materials Science (Mechanical Engineering).