Unidirectional generation of a pure guided wave mode is of practical importance in structural health monitoring (SHM). Currently, unidirectional propagation guided waves can only be generated by using transducer array in a phased array form, which is limited within a very narrow frequency range. If a variable-wavelength unidirectional wave source is required, both the transducer spacing and time delay usually need to be changed with frequency, which is against the permanent arrangement demand of transducers in SHM. In this work, inspired by the unique features of bidirectional SH₀ wave (the fundamental shear horizontal mode) piezoelectric face-shear and thickness-shear transducers, a new method was proposed for generating unidirectional SH₀ wave. Two types of transducer configurations (double-side and single-side) were designed to unidirectionally generate SH₀ wave without frequency-dependent time delay. Both finite element simulations and experiments were conducted to validate the unidirectional features of the proposed double-side and single-side transducer configurations. Results shows that the double-side transducer configuration is capable of generating unidirectional propagation SH₀ wave at the frequency range from 100 kHz to 150 kHz, while the corresponding working frequency range for the single-side one is from 100 kHz to 140 kHz. The proposed method provides a cheap way for generation of the unidirectional SH₀ wave within a certain frequency range without adjusting the relative transducer spacing and the time delay with frequency, so it will have great potential applications in SHM.

单向生成纯导波模式在结构健康监测 (SHM) 中具有实际意义。目前，单向传播导波只能通过使用相控阵形式的换能器阵列产生，其频率范围很窄。如果需要可变波长的单向波源，换能器间距和时延通常都需要随频率而变化，这违背了SHM中换能器的永久布置要求。在这项工作中，受双向 SH ₀波（基本剪切水平模式）压电面剪切和厚度剪切换能器的独特特性的启发，提出了一种产生单向 SH ₀的新方法海浪。设计了两种类型的换能器配置（双面和单面）以单向生成 SH ₀波，而没有频率相关的时间延迟。进行了有限元模拟和实验以验证所提出的双侧和单侧换能器配置的单向特征。结果表明，双侧换能器配置能够在100 kHz至150 kHz的频率范围内产生单向传播的SH ₀波，而单侧换能器的相应工作频率范围为100 kHz至140 kHz。所提出的方法为生成单向 SH ₀提供了一种廉价的方法 无需调整相对换能器间距和随频率的时间延迟，在一定频率范围内的波，因此在SHM中具有很大的潜在应用。