The Combined Effects of Mean Stress and Aggressive Environments on Fatigue Crack Growth

Abstract

Experiments have been performed to study the combined effects of aggressive environment and mean stress on fatigue crack growth. Since mean stress changes also change the stress ratio, R(R = sigma min/sigma max), experiments were performed to measure fatigue crack growth rates for various values of constant R. The experimental results were approximated mathematically using a modified superposition model. The results show that for negative values of R, the modified superposition model yields excellent agreement with the experiments. When R was positive, the mathematical model significantly overestimated the experimental results, suggesting that the full environmental effect condition cannot be achieved in the embrittling system chosen.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1982
Accession Number
ADA116562

Entities

People

  • J. A. Kapp

Organizations

  • United States Army Armament Research, Development and Engineering Center

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Agreements
  • Alloys
  • Crack Tips
  • Cracks
  • Embrittlement
  • Fluid Mechanics
  • Fracture (Mechanics)
  • Liquid Metals
  • Materials
  • Mathematical Models
  • Mechanical Properties
  • Mechanics
  • Military Research
  • Residual Stress
  • Steel
  • Stress Corrosion
  • Stresses

Readers

  • Materials Science (Mechanical Engineering).
  • Mathematics or Statistics
  • Mechanical Engineering/Mechanics of Materials.