APPLICATION OF THE J INTEGRAL TO CRACK INITIATION IN A 2024-T351 ALUMINUM ALLOY

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)

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    Naval Research Laboratory

    4555 Overlook Avenue, SW
    Washington, DC  USA  20375-5320
  • Authors:
    • Griffis, C A
    • Yoder, G R
  • Publication Date: 1974-4-3

Media Info

  • Pagination: 27 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00057232
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • ISBN: RR022-01
  • Report/Paper Numbers: NRL-7676
  • Files: TRIS
  • Created Date: Aug 28 1974 12:00AM