用于厚壁结构中激励低频SH导波的换能器OA

The fundamental shear horizontal(SH0)wave is of practical importance in the structural health monitoring of thick-walled shell structures due to its unique non-dispersive characteristics.However,few transducers are available for exciting low-frequency pure SH0 wave in thick-walled shell structures.In this work,a low-frequency SH0 wave piezoelectric transducer is proposed,which is composed of two anti-symmetrically arranged thickness-shear piezoelectric wafers and a substrate with micro-structures.Both finite element simulations and experimental tests are conducted to examine the performance of the proposed transducer.Results show that the designed piezoelectric transducer can excite a high signal-to-noise ratio(SNR)SH0 wave in the frequency range of 45～65 kHz and focus the wave energy along two opposite directions.In addition,the microstructure design in the substrate can improve the SNR of the SH0 wave excited by the transducer.Experimental results show that the SNR of the SH0 wave excited by the transducer with microstructure is 277%higher than that of the transducer without microstructure.The proposed piezoelectric transducer provides a feasible approach for exciting low-frequency pure SH0 wave in thick-walled shell structures.