Creep relaxation of stress around a crack tip
- Univ. of Pennsylvania, Philadelphia
Plane-strain numerical solutions have been obtained for the power-law creep relaxation of crack tip stresses subsequent to an initial elastic response. Explicit time integration is coupled with an initial-strain, finite element calculation. For cost effective, automatic time step control, the Irons-Treharne-Cormeau stable time step estimate is used to restabilize the calculation between steps 5 to 50 times larger. This finite element scheme is readily adaptable to realistic (and complicated) creep flow relations. Numerical results are presented for the plane-strain shallow Mode I tensile edge crack under constant applied load and creep exponents of 3 and 10. The calculated short-time amplitude of the singular HRR crack tip field under small-scale creeping conditions determines stresses that are within 1.5% of those predicted, using the elastic stress intensity factor K/sub I/ with the Riedel-Rice approximation. This precedes a longer time transition to a steady-state value that is given in terms of the path-independent integral C. Time-dependent crack opening displacements and velocities and the growth of regions where creep strains exceed the elastic strains are also presented.
- OSTI ID:
- 6030060
- Journal Information:
- Int. J. Solids Struct.; (United States), Journal Name: Int. J. Solids Struct.; (United States) Vol. 17:5; ISSN IJSOA
- Country of Publication:
- United States
- Language:
- English
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