Fatigue Crack Growth Characteristics of ARALL (trade name)-1

Abstract

Constant amplitude and spectrum fatigue crack growth rate properties were evaluated for ARALL-1 aluminum laminate. Testing was performed on M(T) specimens under both lab air and high humidity conditions. Crack length monitoring was performed on each aluminum ply utilizing electrical-potential drop techniques to gain a better insight into the fatigue cracking process. Results indicate an outstanding superiority of ARALL-1 in terms of fatigue crack growth resistance over conventionally produced 7000 series aluminum. Fatigue cracking in each of the aluminum plies was fairly uniform, with no large discrepancies in total crack length or growth rates observed between the various plies. For samples tested under a fighter-type load history, the effect of high humidity was actually beneficial, with fatigue crack growth rates typically one- half of those developed under lab air conditions. Explanations based on increased delamination regions are offered to explain this behavior. (JES)

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1988
Accession Number
ADA196185

Entities

People

  • John J. Ruschau

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Aeronautical Laboratories
  • Air Force
  • Air Force Facilities
  • Aramid Fibers
  • Classification
  • Crack Tips
  • Environment
  • Fatigue Cracking
  • High Humidity
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Testing
  • Mechanics
  • Monitoring
  • Plastic Explosives
  • Universities

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Mathematics or Statistics
  • Pavement Materials Engineering.