Ultrasonic Small Incidence Method as a Tool for Sensitive Evaluation of Tightly Closed Smaller Front/rear-wall Cracks

The paper reviews the potential of the ultrasonic small incidence method of testing, which enables us to characterize smaller tight cracks quantitatively under load-free conditions. Recently, an important characteristic of the method of being capable of evaluating the cracks from both the accessible and inaccessible sides of material structures with almost similar level of sensitivity, has been identified. Experimental verification is performed through the evaluation of smaller open as well as tightly closed rear and front-wall cracks in stainless steel samples. Tight closure of the crack is verified by comparing the measured results with those of identical open crack.