THE NON-CONSTANT CTOD/CTOA IN CRACK PROPAGATION
Unlike the common belief that crack propagation behavior can be predicted successfully by employing fracture criteria based on a constant crack tip opening displacement or angle (CTOD/CTOA), this paper shows that the initially non-constant portion of the CTOD/CTOA plays an essential role in predicting the fracture load for a growing crack. Three- and two-dimensional finite element analyses indicate that a severe underestimate of the experimental load vs. crack extension curve would occur if a constant CTOD/CTOA criterion is used. However, the use of a simplified, bilinear CTOD/CTOA criterion including its non-constant portion will closely duplicate the test data. Furthermore, as a result of using the experimental data from J-integral test with various crack length to specimen width ratios (a/W), it is demonstrated that the CTOD/CTOA is crack tip constraint dependent. The initially higher values of the CTOD/CTOA are in fact a natural consequence of crack growth process which is refl ected by the J-resistance curve and its slope (tearing modulus).
- Research Organization:
- Savannah River Site (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC09-96SR18500
- OSTI ID:
- 829694
- Report Number(s):
- WSRC-MS-2004-00532
- Journal Information:
- Journal of the Mechanics and Physics of Solids, Journal Name: Journal of the Mechanics and Physics of Solids
- Country of Publication:
- United States
- Language:
- English
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