THE EFFECT OF CRACK SHAPE ON FRACTURE TOUGHNESS.
Abstract
An investigation was made to determine the effect of crack eccentricity upon fracture toughness. Fracture toughness tests, using partial thickness crack (PTC) coupons, were performed on two heats and three thick nesses of the l8Ni-9Co-5Mo (300 psi) maraging steel. In addition, data on tempered 4340 steel and aged Ti-6Al6V-2Sn were taken from the literature and analyzed. The results to date indicate: l. Crack ellipticity need not be considered if the gross fracture strength is represented as a function of crack length. However, crack eccentricity must be considered if gross fracture strength is represented as a function of crack depth or crack area. 2. Irwin's constant, as defined by Irwin's equation, is not a constant when eccentricity is varied, and should not be used to judge fracture toughness unless the eccentricity of the cracks has been kept constant. 3. A new parameter, C, similar to Irwin's constant, is introduced. This, unlike Irwin's constant, is apparently unaffected by crack eccentricity. It is suggested that this new parameter might have a wider application than Irwin's constant. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 27, 1964
- Accession Number
- AD0604056
Entities
People
- D. L. Corn
- W. V. Mixon
Organizations
- Douglas