Measures of Bulk and Grain Strain in Deformation Processes(PREPRINT)

Abstract

Many instances of severe plastic deformation produce a heterogeneous distribution of strain through a material. Common methods of describing the severity of deformation based on changes in the external dimensions of a specimen masks this heterogeneity, which is difficult to measure directly. This study describes a method of measuring internal strain based on the observation that networks of internal boundaries within a polycrystalline material deform locally in a manner congruent with the local metal flow. Appropriate measurements of the development of the spatial anisotropy of such networks with increasing deformation provide a basis for defining several measures of the local total strain. These quantities, called "grain strains" when the boundaries observed are grain boundaries, can serve as an experimental measure of the internal total strain in various locations in a specimen for comparison with computations based on finite element models using various constitutive relations.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2007
Accession Number
ADA470126

Entities

People

  • Craig S. Hartley
  • Jonathan E. Spowart

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Anisotropy
  • Boundaries
  • Coordinate Systems
  • Crystal Lattices
  • Equations
  • Grain Boundaries
  • Materials
  • Materials Laboratories
  • Measurement
  • Mechanical Properties
  • Military Research
  • Plastic Deformation
  • Research Facilities
  • Three Dimensional
  • Two Dimensional

Readers

  • Calculus or Mathematical Analysis
  • Mechanical Engineering/Mechanics of Materials.
  • Systems Analysis and Design