Fatigue Crack Arrest Problem of Thick-Walled Cylinders under Thermal Stress : (1st Report, Preliminary Study by Single Edge Cracked Strip)

摘要

There is a rule of thumb'on thick-walled cylinders, that is'the circumferential fatigue cracks under thermal stress will be arrested at 1/3～1/2 of the wall thickness'. In our study, the reason why crack tends to arrest will be made clear, and practical formula to estimate arrest point will be proposed. In this paper, effect of thermal stress distribution on fatigue crack arrest is examined, on the case of single edge cracked strip. It was derived that the stress intensity factor distribution is a product of a tunction of structural compliance and the equivalent moment calculated from the thermal stress distribution. From this fact, it was concluded that characteristics of crack growth rate (including tendency of arrest) under cyclic thermal stress is dominated by structural compliance, assuming Paris'Law.