中文摘要：

接收信号在压电换能器压电层中的多次反射及波形转换对超声检测的灵敏度和分辨率有重要影响，如何优化阻尼结构与材料参数是提高压电换能器接收性能的关键之一。本文用ANSYS有限元软件中的力-电耦合瞬态模拟方法，研究了压电直探头中阻尼结构的几何尺寸及声阻抗对其瞬态响应的影响，得到了压电换能器中不同时刻的弹性波场、电场分布以及输出电压响应曲线，揭示了换能器瞬态响应产生的多次反射波对其检测灵敏度和分辨率的影响。研究结果表明：通过改进的阻尼结构与材料参数对消减接收信号的多次反射，缩短余振时间具有明显的作用，也可以大大降低换能器的研发周期和成本。

英文摘要：

Due to structural parameters and acoustic impedance differences of piezoelectric transducers, unwanted reflection and wave conversion of the receiving signals occur,which will reduce sensitivity and resolution of an ultrasonic inspection system. The study is performed in this paper to reduce these reflection differences with the usual way. With a finite element modeling program ANSYS, several transducer configurations with different damping structure parameters and acoustic impedances are simulated. From the simulation, the wave field and electric field snapshots and voltage response waveforms are acquired, which make it possible to pinpoint the causes of reflection. It is found that the proper design can improve the performances of the transducers significantly. The results show that the finite element method is useful to the design analysis and can decrease the development time and cost of the piezoelectric transducers drastically