用于厚壁结构中激励低频SH导波的换能器  

A Transducer for Exciting Low-frequency SH Guided Wave in Thick-walled Structure

作　　者：张尧 阚前华[1] 苗鸿臣 ZHANG Yao;KAN Qianhua;MIAO Hongchen(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学力学与航空航天学院,成都611756

出　　处：《四川轻化工大学学报（自然科学版）》2024年第1期27-34,共8页Journal of Sichuan University of Science & Engineering(Natural Science Edition)

基　　金：国家自然科学基金项目(12172310);四川省应用基础研究面上项目(2022NSFSC0435);中国科协青年人才托举工程项目(YESS20210342)。

摘　　要：零阶水平剪切波(SH_(0)波)因其独特的非频散(即波速不随频率改变)特性在厚壁板壳结构的智能监测中具有可观的应用前景。然而,当前能够在厚壁板壳结构中激励单模态低频SH_(0)波的换能器十分匮乏。鉴于此,本研究设计了一种低频SH_(0)波压电换能器,该换能器由两个反对称布置的厚度剪切压电晶片和一个含有微结构的基底构成。有限元仿真和实验结果表明,该压电换能器可以在45~65 kHz频率范围内激励高信噪比的SH_(0)波,且能够将SH_(0)波的能量聚焦在两个相反的主方向。此外,基底中的微结构设计可以提高换能器激励的SH_(0)波的信噪比,基底有微结构的换能器所激励的SH_(0)波的信噪比比基底无微结构的换能器提高了277%。本研究所提出的压电换能器可为在厚壁板壳结构中激励单模态的低频SH_(0)波提供一个可行的途径。The fundamental shear horizontal(SH_(0))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 SH_(0) wave in thick-walled shell structures.In this work,a low-frequency SH_(0) 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)SH_(0) 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 SH_(0) wave excited by the transducer.Experimental results show that the SNR of the SH_(0) 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 SH_(0) wave in thick-walled shell structures.

关 键 词：导波 水平剪切波 压电换能器 结构健康监测 厚壁结构 

分 类 号：TU317[建筑科学—结构工程]