PVDF comb transducers for ZGV Lamb waves detection and its performance study
The transducer that can accurately excite and respond to zero group velocity(ZGV)Lamb waves is crucial for the application of ZGV Lamb waves detection.The traditional transducers used for ZGV Lamb waves detection suffer from issues such as weak signals and low signal-to-noise ratio.In this paper,a polyvinylidene fluoride(PVDF)comb transducer with good flexibility and high sensitivity is designed,and the excitation response performance of the transducer to ZGV Lamb waves is studied.Firstly,the operating characteristics of the comb transducer are analyzed,and the PVDF comb transducer is designed and manufactured according to the ZGV mode of a thin aluminum plate.Subsequently,the ZGV Lamb waves were excited by the PVDF comb transducer under the pulse signals with different center frequencies,and performance comparison experiments were conducted with PVDF square electrode transducers Finally,the relationship between the voltage response characteristics of the PVDF comb transducer and the thickness of the attachment layer was analyzed.Experimental results demonstrate that the PVDF comb transducer designed and manufactured can accurately excite and respond to the ZGV Lamb waves.Moreover,the relative amplitude of the ZGV frequency domain of the response signals decreases significantly with the increase of the thickness of the attachment layer.