CONSTITUTIVE EQUATIONS FOR ELASTIC-PLASTIC MATERIALS AT FINITE STRAIN,

Abstract

Constitutive equations are suggested for describing the behavior of elastic-plastic materials undergoing large strains. A special kinematical viewpoint is taken, so that the elastic and plastic deformation processes can be considered separately. This separation is also accomodated by a simplified thermodynamical theory of the deformation process. The general elastic constitutive equation is written as a rate equation, after examining the interpretation of elastic isotropy in view of the particular kinematical description employed. To describe plastic deformation, a general rate equation, which exhibits no dependence on the rate at which previous states have been traversed, is suggested. After the general relations have been put in appropriate form some simplifications based on physical assumptions are considered. The physical assumptions are based on the behavior of metals under large stress, high speed loading, such as in the penetration problem. Under these operating conditions, the thermoelastic effects dominate and plasticity plays a minor role. Consequently, a simple model of plastic deformation usually suffices. The analysis is presented in direct (matrix) notation and is valid for arbitrary stress states. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1969
Accession Number
AD0692475

Entities

People

  • Lambert Ben Freund

Organizations

  • Brown University

Tags

DTIC Thesaurus Topics

  • Constitutive Equations
  • Differential Equations
  • Equations
  • Equations Of State
  • Materials
  • Mathematics
  • Notation
  • Partial Differential Equations
  • Plastic Deformation
  • Plastic Properties

Readers

  • Calculus or Mathematical Analysis
  • Mechanical Engineering/Mechanics of Materials.
  • Theoretical Analysis.