FATIGUE CRACK PROPAGATION UNDER PROGRAMMED AND RANDOM LOADS

Abstract

The influence of maximum stress, stress range, and sequence of load application on the rate and mechanism of fatigue crack propagation in 2024-T3 aluminum alloy was studied by means of electron fractography. The macroscopic growth rates were determined on center-notched crack growth panels and the fracture surfaces were examined by electron fractography. An empirical equation relating relative microscopic growth rates at a given crack length to maximum loads and load amplitudes was obtained. It was also found that the advance of a fatigue crack front takes place only during the loading part of a cycle and that in the pseudorandom load case the sequence of load application can markedly influence crack growth rate on any one cycle.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1966
Accession Number
AD0650417

Entities

People

  • J. C. Mcmillan
  • Regis N. Pelloux

Organizations

  • Boeing

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Aluminum Alloys
  • Amplitude
  • Computer Programs
  • Computers
  • Crack Propagation
  • Crack Tips
  • Cracks
  • Crystal Structure
  • Electron Microscopes
  • Electron Microscopy
  • Equations
  • Fatigue Cracking
  • Intensity
  • Materials
  • Microscopes
  • Physics Laboratories

Readers

  • Computer Programming and Software Development.
  • Materials Science and Engineering.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).

Technology Areas

  • Microelectronics