A SAFT algorithm for lamb wave imaging of isotropic plate-like structures

摘要

Synthetic aperture focusing technique (SAFT) algorithm in the Fourier domain (F-SAFT) has been modified to take into account the dispersive nature of Lamb waves. This new algorithm can be used to produce good ultrasonic images of a plate structure for both dispersive and non-dispersive parts of the Lamb wave dispersion curve. This imaging technique has been tested by performing an inspection in a highly dispersive area of the fundamental flexural S_(0) mode in order to demonstrate the usefulness of the new algorithm. Results are presented as a comparison between standard B-scan, original F-SAFT algorithm and new Lamb-SAFT algorithm.