ON STRAIN INCOMPATIBILITY AND GRAIN BOUNDARY DAMAGE IN FATIGUE.

Abstract

It is shown by observation of the cyclically deformed structure of Fcc metals that even under conditions of slip concentrated in bands, the restraint by neighboring grains significantly affects the damage developing in these bands. At higher strain amplitudes at which slip is not concentrated the restraint by neighboring grains produces grain boundary damage. The concept of strain incompatibility used to interpret the observations also implies that typical surface phenomena observed in fatigue such as notches and stiles in the surface at low strain amplitudes and rumpled surfaces due to grain distortion at high strain amplitudes are mechanisms for the relief of strain incompatibilities rather than primary causes of fatigue damage, while the significance of subgrain formation with respect to fatigue changes in the course of cyclic straining. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1964
Accession Number
AD0607224

Entities

People

  • Maria Ronay

Organizations

  • Columbia University

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Boundaries
  • Crystal Structure
  • Distortion
  • Grain Boundaries
  • Observation

Readers

  • Materials Science and Engineering.
  • Structural Health Monitoring of Composite Structures.