STRESS FIELDS AND INTERACTION STRESSES OF DISLOCATIONS NEAR FREE SURFACES.

Abstract

The expressions for the stress fields of screw and edge dislocations near free surfaces in anisotropic cubic crystals are developed using analytic or variational methods. The screw dislocation had its axis along <110> and was oriented on a (111) plane either intersecting or parallel to the surface. In the case for an edge dislocation, the axis was aligned with a <112> direction. By using the stress fields for the dislocations oriented parallel to the surface, the stresses required for dislocations to pass one another are compared with those encountered in an infinite medium. It was concluded that in some cases it is more difficult for dislocations to pass each other when under the influence of the surface than in the bulk. The effects of anisotropy are compared with the isotropic approximation. Also, the behavior of dissociated dislocations near free surfaces is discussed with a numerical example given. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1969
Accession Number
AD0690201

Entities

People

  • H. G. F. Wilsdorf
  • K. H. Cotter Jr.

Organizations

  • University of Virginia

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Anisotropy
  • Calculus
  • Calculus Of Variations
  • Diseases And Disorders
  • Dislocations
  • Mathematics
  • Variational Methods

Readers

  • Fluid Dynamics.
  • Materials Science and Engineering.