Application of the J Integral to Crack Initiation in a 2024-T351 Aluminum Alloy,

Abstract

The J integral has been successfully applied as a fracture initiation criterion for 2024-T351 aluminum alloy. A heat-tinting technique was used for quantitative measurement of crack extension at selected points on the load-deflection curve. In three-point bend tests incorporating six specimen configurations the critical J values (J(Ic)) at the onset of crack movement differ by at most 15 percent and yield a mean K(Ic) value of 30.9 plus or minus 1.2 ksi/(in. superscript 1/2). The relationship between instantaneous J value and crack extension is independent of initial crack length over the range of crack sizes investigated. J-integral values associated with maximum load (5 to 15 percent crack growth), unlike J(Ic), show a strong dependence on specimen thickness. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 03, 1974
Accession Number
AD0777999

Entities

People

  • C. A. Griffis
  • George R. Yoder

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Deflection
  • Integrals
  • J Integrals
  • Mathematics
  • Measurement
  • Thickness

Readers

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