Sizing of surface-breaking cracks in complex geometry components by ultrasonic Time-of-Flight Diffraction (TOFD) technique

Sizing a surface-breaking crack in a complex geometry component, for example a steam turbine's solid rotor shaft, is a challenging inspection task. This paper deals with experimental work for the evaluation of the Time-of-Flight Difftaction (TOFD) technique for sizing of surface-breaking cracks in such a complex geometry component. The experimental results show that with the help of the mathematical model explained here, TOFD can size such cracks with reasonable accuracy.