The Study on Scattered Far-Field Analysis of Ultrasonic SH-Wave Using Boundary Element Method

It is well recognized that ultrasonic technique is one of the most common and reliable nondestructive evaluation techniques for quantitative estimation of defects in structures. For the quantitative and accurate estimation of internal defects, the characteristics of scattered ultrasonic wave fields must be understood. In this study. the scattered near-field and far-field due to a circular cavity embedded in infinite media subjected to incident SH-waves were calculated by the boundary element method. The frequency response of the scattered ultrasonic far-field was transformed into the time-domain signal by obtaining its inverse Fourier transform. It was found that the amplitude of time-domain signal decreases and its time delay increases as the distance between the detecting point of ultrasonic scattered field and the center of internal cavity increases