Abstract
Computer simulations revealed that multiple reflections of Lamb waves occur at a delamination and a square notch in plates in our previous work. In this study, a single mode extraction technique was developed to confirm the multiple reflections. Since the Lamb waves scattered at defects consist of many dispersive modes, it is difficult to identify a particular mode and estimate characteristics of defects from such signals. The single mode extraction is base on two-dimensional FFT of received signals in time and space, filtering and 2D inverse FFT. Air-couple transducers were adopted for non-contact fast data acquisition. Using this technique, A0 and S0 modes were clearly separated in preliminary tests of intact plates. Furthermore, the multiple reflections of an A0 mode were observed in reflection tests of plates with a square notch. The reflected waves from the edges of the square notch were identified in the extracted A0 mode as two wave packets. The time of flight gave the widths of notches.
Submitted Version (
Free)
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call