A NUMERICAL AND EXPERIMENTAL INVESTIGATION OF THE USE OF J-INTEGRALS

Finite element analysis was used to determine numerically Rice's J-integral values in centrally notched plates of 4340 steel. These numerical values were compared with corresponding J-integral values using Dugdale model and antiplane strain model with a power law hardening of n equals 0.3. J-integral was also computed for a crack extending into its own plastic yield region under constant loading. For increasing level of loading, the rate of increase in J-integral decreases and J-integral remains almost constant at a loading ratio of 1 under such crack extension. A limited number of fracture tests were conducted with centrally notched 4340 steel specimens heat treated to yield strength levels of 150, 180, 210 and 240 ksi. Fracture data showed that the critical J-integral, calculated and measured, is insensitive to crack tip sharpness for the lower strength 4340 material and thus the J sub c fracture criteria appears suited in correlating fracture data.

• Supplemental Notes:
  • Sponsored by Office of Naval Research, Arlington, Virginia, and by the Army Research Office (Durham).
• Corporate Authors:

  University of Washington, Seattle

  Department of Mechanical Engineering
  Seattle, WA  United States  98105
• Authors:
  • Kobayashi, A S
  • Chiu, S T
  • Beeuwkes, R
• Publication Date: 1972-5

Media Info

• Features: References;
• Pagination: 29 p.

Subject/Index Terms

• TRT Terms: Cracking; Finite element method; Fracture mechanics; Materials tests; Steel
• Uncontrolled Terms: Crack propagation
• Old TRIS Terms: Steel testing
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00035681
• Record Type: Publication
• Source Agency: Ship Structure Committee
• Report/Paper Numbers: Tech Rpt
• Contract Numbers: N00014-67-A013080018, DA-31-124-ARO(D)-112
• Files: TRIS
• Created Date: Oct 13 1973 12:00AM