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)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/RR02201
• Corporate Authors:

  Naval Research Laboratory

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

Media Info

• Pagination: 27 p.

Subject/Index Terms

• TRT Terms: Aluminum alloys; Cracking; Fracture mechanics; Stresses
• Uncontrolled Terms: Crack propagation; Stress intensity factors
• Subject Areas: Marine Transportation; Materials;

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