Equilibrium Conditions for the Average Stresses Measured by X-Rays.

Abstract

True macro-stresses are measured with x-rays after material processing, only if there is a uniform plastic deformation in the sampled volume that is different than that in the rest of the material. In this stress-field the components in the direction of the surface normal are usually negligible over the depth penetrated by x-ray (for example, peening). However, pseudo-macrostresses, or backstresses, arise when this condition is violated, for example, if there are second phase particles and there is a gradient of plastic deformation from particle to matrix. This pseudo-macrostress field is three-dimensional and the stresses in the direction of the surface normal can be measured with x-rays. Equations are presented which allow estimates to be made of the magnitudes of the two kinds of stress fields.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1982
Accession Number
ADA120750

Entities

People

  • I. C. Noyan

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundaries
  • Composite Materials
  • Differential Equations
  • Equations
  • Materials
  • Materials Science
  • Measurement
  • Military Research
  • Modulus Of Elasticity
  • Plastic Deformation
  • Precipitates
  • Residual Stress
  • Shear Stresses
  • Shot Peening
  • Stresses
  • Three Dimensional
  • X Rays

Readers

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