Quantitative approaches to flaw sizing based-on ultrasonic testing models

Flaw sizing is one of the fundamental issues in ultrasonic nondestructive evaluation of various materials, components and structures. Especially, for cracks, accurate sizing is very crucial for quantitative structural integrity evaluation. Therefore, robust and reliable flaw sizing methods are strongly desired. To address such a need, using ultrasonic testing models, we propose quantitative model-based flaw sizing approaches such as 1) construction of DGS (Distance-Gain Size) diagrams, 2) suggestion of a criterion for the proper use of the 6 dB drop method, and 3) proposal of a reference curve named as the SAC (Size Amplitude Curve) for sizing of vertical cracks. The accuracy of the proposed approaches is verified by the initial experiments.