Ultrasonic time-of-flight diffraction crack size identification based on cross-correlation

The time-of-flight-diffraction (TOFD) ultrasonic detection method has been widely used in defect size assessment. This paper presents a method using cross correlation to improve the accuracy of defect sizing in the TOFD framework. The resulting peaks of the cross correlation function between two signals indicate the time of flight between them. Experimental results are used to demonstrate the advantage of the proposed method.