宽频带梯形叉指式换能器优化设计及应用

由声表面波（Surface Acoustic Wave）器件发展而来的叉指换能器（Interdigital Transducer，IDT）由于其工作频率可以设计、频带宽可调、损耗低等特点逐步应用于结构健康监测（Structural Health Monitoring，SHM）系统中，因此在智能材料与结构中有着广泛的应用前景。本文针对现有矩形IDT带宽窄的不足，研究宽频带梯形叉指换能器（Trapezoidal Interdigital Transducer，TIDT）。采用有限元分析方法对TIDT的尺寸进行结构优化设计，并对设计的TIDT进行性能测试，通过实验研究了TIDT用于结构损伤检测的初步应用。实验结果表明，TIDT在实际应用中进一步提高了损伤识别精度，具有广泛的应用前景。

Research on the Optimal Design and Application of Wideband TIDT Structures

The interdigital transducer (IDT), developed from surface acoustic wave devices, has been gradually applied to structural health monitoring systems due to its operating frequency, adjustable frequency bandwidth and low loss. Therefore, it has a wide application prospect in smart materials and structures. In this paper, the wideband trapezoidal interdigital transducer (TIDT) is studied for the shortage, narrow bandwidth, of the existing rectangular IDT. The finite element analysis method was used to optimize the TIDT structure, and the TIDT performance was tested. The preliminary application of TIDT for structural damage detection was studied through experiments. The experimental results show that TIDT improves damage recognition accuracy in practical applications and has broad application prospects.