A STUDY OF THE THERMODYNAMICS OF ONE-DIMENSIONAL DEFORMATIONS OF NONLINEAR MATERIALS CHARACTERIZED BY QUASILINEAR DIFFERENTIAL CONSTITUTIVE EQUATIONS.

Abstract

The thermodynamics of one-dimensional deformations of materials of first-order quasilinear differential type is studied on the basis of the assumption that the strain is the sum of a 'rate-independent' and a 'rate-dependent' part, and that the material time derivative of the latter, but not of the former, is a kinematical variable of state. This assumption is shown to lead to the most general isothermal constitutive equation of such a material. Furthermore, non-isothermal behavior can be predicted from the isothermal characteristic functions at various temperatures. A distinction is made between viscoelastic and viscoplastic materials on the basis of the continuity (or lack of it) of the rate equation with respect to strain rate. For viscoelastic materials the functional form of the free-energy density is determined completely, and specific examples of such materials are discussed. Viscoplastic materials are discussed with regard to yield condition and relationship to plastic materials. The validity of the development for three-dimensional deformations is remarked upon. (Author)

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1967
Accession Number
AD0822678

Entities

People

  • J. Lubliner

Organizations

  • University of California, Berkeley

Tags

DTIC Thesaurus Topics

  • Constitutive Equations
  • Continuity
  • Energy
  • Equations
  • Equations Of State
  • Free Energy
  • Materials
  • Mathematics
  • Strain Rate
  • Thermodynamics
  • Three Dimensional

Readers

  • Calculus or Mathematical Analysis
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Materials Science and Engineering.