Dislocation Dynamics and the Formulation of Constitutive Equations for Rate-Dependent Plastic Flow in Metals

Abstract

A rate-dependent constitutive model is developed which describes a broad spectrum of elastic-plastic response in isotropic metals, ranging from quasi-static behavior through the thermally activated intermediate strain rate regime, up to the high strain rate region where phonon viscosity and relativistic effects appear to control the flow process. Upon reverse straining from a plastically prestrained state, the constitutive model exhibits a rate- dependent Bauschinger effect. An attempt has been made to utilize, wherever possible, current knowledge in the theory of dislocation dynamics in formulating the constitutive model. In most cases, only simple models of governing deformation mechanisms can be constructed and, even to accomplish this, considerable speculation sis required. Where dislocation theory is unable to provide guidance in defining and characterizing a particular mechanism, a phenomenological approach has been followed. The advanced constitutive model developed here has been incorporated into the one-dimensional, finite-difference RIP code. The application of this model to 6061-T6 aluminum is described.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1970
Accession Number
AD0722314

Entities

People

  • Harold E. Read
  • John R. Triplett
  • Robert A. Cecil

Organizations

  • Utility Systems Science and Software (United States)

Tags

Communities of Interest

  • Air Platforms
  • Counter WMD
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Constitutive Equations
  • Crystal Lattices
  • Crystal Structure
  • Dynamic Response
  • Dynamics
  • Equations
  • Equations Of State
  • Materials
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Shear Stresses
  • Strain Hardening
  • Stress Strain Relations
  • Stress Waves
  • Stresses

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Theoretical Analysis.