Leader of group, Fracture and Damage Mechanics, Sulzer Bros., Ltd., Winterthur,
Honorary research fellow, Imperial College of Science and Technology, London,
Pages: 16 Published: Jan 1990
The new method of surface crack growth calculation under linear elastic fracture mechanics (LEFM) conditions facilitates the use of stress-intensity factor K (and in particular its ΔK range) as a tool to estimate the fatigue life of cracked plates under tensile loads. This is made possible by determining a set of parameters in order to obtain equal ΔK values and analogous crack propagation rates in two widely different specimen geometries, a plate and a standard compact type (C(T)) specimen. A comparison of fatigue lives with equivalent crack growth for both types of specimen suggests that in using the proposed procedure, the significance of ΔK values in a part-through crack is closely related to that of a through crack in a C(T) specimen.
In analyzing the surface crack growth under elastic-plastic conditions, it should be necessary to use J values in a different way than in LEFM. Appropriate references to both problems are quoted.
three-dimensional crack problems, fatigue, specimen-to-structure correlation, stress-intensity factor , K, energy integral , J, surface crack, pressure vessels, pipes
Paper ID: STP23439S