Polycrystalline Plastic Deformation and Texture Evolution for Crystals Lacking Five Independent Slip Systems

Abstract

WE clearly elucidate the kinematic constraints, and the corresponding kinematic indeterminacy of part of the deviatoric stress tensor, in a rigid- viscoplastic single crystal lacking five independent slip systems. The indeterminate stress component is a Lagrange multiplier enforcing the kinematic constraint, and it must be determined from equilibrium considerations. A simple polycrystalline model is constructed which precisely satisfies local kinematic constraints as well as global compatibility. Volume-average global stresses are obtained by approximating the local constraint stress as the corresponding projection of the (to-be-determined) global stress. Applications of the model to hexagonal crystals without pyramidal slip, and to large deformation and texturing of orthorhombic polycrystalline materials (olivine; HDPE) are made. Keywords: Plastic flow in polycrystals; Aggregates of insufficient slip systems; simulation of texture evolution.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
May 29, 1989
Accession Number
ADA208902

Entities

People

  • David M. Parks
  • Said Ahzi

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Crystal Lattices
  • Crystal Structure
  • Crystals
  • Equations
  • Four Dimensional
  • Hardening
  • Materials
  • Mechanical Engineering
  • Mechanics
  • Plastic Deformation
  • Plastic Flow
  • Polycrystals
  • Shear Stresses
  • Simulations
  • Single Crystals
  • Strain Rate
  • Stress Strain Relations

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Operations Research