An application of the J-integral to an incremental analysis of blunting crack behavior
- Oak Ridge National Lab., TN (USA)
This paper describes an analytical approach to estimating the elastic-plastic stresses and strains near the tip of a blunting crack with a finite root radius. Rice's original derivation of the path independent J-integral considered the possibility of a finite crack tip root radius. For this problem Creager's elastic analysis gives the relation between the stress intensity factor K{sub I} and the near tip stresses. It can be shown that the relation K{sub I}{sup 2} = E{prime}J holds when the root radius is finite. Recognizing that elastic-plastic behavior is incrementally linear then allows a derivation to be performed for a bielastic specimen having a crack tip region of reduced modulus, and the result differentiated to estimate elastic-plastic behavior. The result is the incremental form of Neuber's equation. This result does not require the assumption of any particular stress-strain relation. However by assuming a pure power law stress-strain relation and using Ilyushin's principle, the ordinary deformation theory form of Neuber's equation, K{sub {sigma}} K{sub {var epsilon}} = K{sub t}{sup 2}, is obtained. Applications of the incremental form of Neuber's equation have already been made to fatigue and fracture analysis. This paper helps to provide a theoretical basis for these methods previously considered semiempirical. 26 refs., 4 figs.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- Sponsoring Organization:
- USNRC
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5659252
- Report Number(s):
- CONF-8910199-1; ON: DE89016844; TRN: 89-024715
- Resource Relation:
- Conference: European symposium on elastic-plastic fracture mechanics, Freiburg (Germany, F.R.), 9-12 Oct 1989
- Country of Publication:
- United States
- Language:
- English
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