Finite element simulation of creep-crack growth in a nickel base superalloy

Creep-crack growth in a standard compact-tension specimen has been simulate d for an elastic/power-law creeping material, Waspaloy, at 650 degreesC usi ng the finite element code ABAQUS. Two cases of crack growth rates, relativ ely fast (3.25 x 10(-2) mm/h) and slow (3.25 x 10(-5) mm/h), were considere d. For both cases, the ratio of the load-line deflection rate due to creep (V-c) to the total deflection rate (P) was found to be well below unity, i. e., (V) over dot(c) / (V) over dot(c) much less than 1, which suggests the creep-brittle characteristics. The development of the creep zone was determ ined and the creep-zone expansion rate along the crack growth direction was compared to the crack growth rate. Attempts were made to describe the crac k tip stress fields by the Hui-Riedel, Hutchinson-Rice-Rosengren and K type s at different stages of crack growth. (C) 2001 Elsevier Science Ltd. All r ights reserved.