MICROSCOPIC MOVIE OF FATIGUE INDUCED CRACK INITIATION AND PROPAGATION,

Abstract

A motion picture taken through an optical microscope was made in an attempt to better understand the mechanisms of fatigue crack initiation, propagation and fracture in metals. The primary usage of the movie is that of a visual educational training aid. The movie qualitatively compares crack initiation and propagation in a low carbon steel under the following conditions: (a) low cycle fatigue (less than 50,000 cycles to failure) photographed at 16X, 150X, and 300X magnification; (b) high cycle fatigue (about 1 million cycles to failure) photographed at 300X magnification. Under these conditions the movie shows the interaction of slip lines, slip bands, crack tip, grains and grain boundaries under cyclic conditions. (Author)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1969
Accession Number
AD0698017

Entities

People

  • R. E. Duncan
  • R. I. Stephens

Organizations

  • University of Iowa

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Carbon Steels
  • Crack Tips
  • Cracks
  • Grain Boundaries
  • Magnification
  • Microscopes
  • Motion Pictures
  • Steel
  • Training
  • Vibration

Readers

  • Educational Psychology
  • Materials Science (Mechanical Engineering).