Design of Low Frequency Piezoelectricity Transducer for Excitation of Pure A_0 Lamb Wave and Its Application in Nondestructive Testing

To excite the single Lamb wave mode for non-destructive detection in plates,a low frequency piezoelectric transducer for exciting single-mode Lamb wave is designed.Based on theoretical model and finite element simulation model,the frequency response of piezoelectricity transducer is investigated.The influence of the parameters of backing mass and interface,such as thickness,density and elastic modulus are foused.Meanwhile,the performance testing of piezoelectric transducers with different structural parameters are conducted.The influences of parameters of transducer to the frequency characteristics and excitation waveform are investigated.As a result,a piezoelectric transducer is designed to excite low-frequency A0 mode Lamb wave in plates.The designed piezoelectric transducers are constituted into array for non-destructive testing in plates.