Comparison of Theoretical Estimates and Experimental Measurements of Fatigue Crack Growth Under Severe Thermal Shock Conditions—Part I: Experimental Observations

This paper reports the results of an experiment in which a severe thermal cycle comprising of alternate upshocks and downshocks has been applied to an axisymmetric feature with an internal, partial penetration weld and crevice. The direction of cracking and crack growth rate were observed experimentally and detailed records made of the thermal cycle. A second part of the paper, reported separately, compares a linear elastic fracture mechanics assessment of the cracking to the experimental observations.