EXPERIMENTAL STUDY ON DEFECT IMAGING BASED ON SINGLE LAMB WAVE MODE IN PLATE-LIKE STRUCTURES

Lamb wave technology is used for defect detection in plate-like structures. It is easier to interpret received signals and to identify defects if single mode Lamb waves are applied. In this study, piezoelectric transducers are attached, in a form of arrays, on the top and bottom sides of plate. When two piezoelectric transducers at the same locations on each side of the plate are excited by voltage signal simultaneously in phase or out phase, single S₀ mode or A₀ mode is generated, respectively. In combination with the elliptic imaging algorithm and the data fusion method, single Lamb wave mode can be used for defect imaging for multiple signals received by piezoelectric transducer arrays. The method proposed in this study is effective to obtain two-dimensional images of defects and detect artificial defects in plate-like structures, with improved recognition ability and accuracy.