Constitutive Equations for Cyclic Loading of Rate Dependent Materials.

Abstract

The constitutive equations that have been developed by the authors to represent elastic-viscoplastic, strain-hardening materials have been modified to apply to changes in the direction of stressing. This modification involves altering the strain-hardening parameters with a change in the sign of the stress and also adding a linear viscosity term to the plastic deformation rate. These modifications are shown to have a physical basis and enable the constitutive equations to predict the general features of cyclic stress-strain behavior at various extensions rates and strain amplitudes including the tendency toward a limit cycle. An unusual feature of cyclic loading tests on some metals is a local concavity of the stress-strain curve which is predicable by these equations. Cyclic stress-strain curves were calculated for titanium for various conditions and compared to corresponding experimental results.

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1976
Accession Number
ADA027655

Entities

People

  • S. R. Bodner
  • Y. Partom

Organizations

  • Technion – Israel Institute of Technology

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Constitutive Equations
  • Differential Equations
  • Equations
  • Hardening
  • Materials
  • Mathematics
  • Mechanical Properties
  • Metals
  • Physical Properties
  • Plastic Deformation
  • Strain Hardening
  • Stress Strain Relations
  • Stresses
  • Titanium

Readers

  • Fluid Dynamics.
  • Materials Science (Mechanical Engineering).
  • Mathematics or Statistics