Fracture toughness results and preliminary analysis for International Cooperative Test Program on specimens containing surface cracks
- Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering Lab.
- Lockheed Martin Corp., New Orleans, LA (United States). Manned Space System
- Engineering Material Research, Downsview, Ontario (Canada)
- NASA Langley Research Center, Hampton, VA (United States)
- Univ. of Karlsruhe (Germany)
- NASA Ames Research Center, Moffett Field, CA (United States)
Specimens containing surface cracks were tested in either tension or bending to compare the stress intensity factor at failure with plane strain fracture toughness (K{sub Ic}) in an International Cooperative Test Program. The material was heat treated to {sigma}{sub ys} = 1 587 MPa and K{sub Ic} = 54 MPa m{sub 1/2}. Because substantial stable crack growth occurred for some specimens, the test plan was modified to include detecting the onset of crack growth. It is shown that P{sub max} and the original fatigue precrack size cannot be employed to calculate K{sub max} for comparison with K{sub Ic} when significant stable crack growth occurs. However, using P{sub init} (load at which stable crack growth is initiated) and the original fatigue precrack size to calculate K{sub max} or K{sub {phi}=30{degree}} provides a very useful comparison with K{sub Ic}. The influence of variations in fatigue precrack configuration on test results are also discussed.
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC07-94ID13223
- OSTI ID:
- 566581
- Report Number(s):
- CONF-9606178--
- Country of Publication:
- United States
- Language:
- English
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