一种分析非均匀厚度1-3型压电复合材料换能器性能的方法

非均匀厚度1-3型压电复合材料可用于制作宽带压电换能器,已广泛应用于水浸无损探伤、声波测井以及超声成像等领域。为分析该换能器的振动及其性能,提出了一种并联振子等效电路模型,将非均匀厚度1-3型压电复合材料换能器看成并联的谐振器阵列,采用三维厚度伸缩振动模型对单个谐振器单元进行理论分析,得出了非均匀厚度1-3型压电复合材料换能器的阻抗计算公式;为验证该模型的正确性,设计并制作了一个平凹的1-3型压电复合材料换能器;实验结果显示,并联振子等效电路模型能准确的分析非均匀厚度1-3型压电复合材料片的性能。结果表明,非均匀厚度换能器带宽的主要是由压电片的厚度差异决定,研究结果可为非均匀厚度宽带换能器的设计提供参考。

A method on analyzing the performance of a 1-3 piezoelectric composites with non-uniform thickness

1-3 piezoelectric composites transducers with non-uniform thickness which have characteristics of wide bandwidth are widely used in the fields of underwater ultrasonic testing, sonic logging, and ultrasonic imaging. In this paper, an equivalent circuit model of a parallel-connected resonator arrays was proposed to analyze the vibration and performance of the transducer. When a 1-3 piezoelectric composite plate was designed to have a gradually varying thickness, the plate could be regarded as composed of parallel-connected oscillator arrays with various thicknesses. And a 3D thickness-stretching vibration model was employed to analyze the single resonator unit. Impedance of non-uniform thickness 1-3 piezoelectric composite transducer was achieved. To verify the theory, a transducer using a flat-concave 1-3 piezoelectric composite plate was fabricated. The experiment results agree well with the theory, indicating that the equivalent circuit model of a parallel resonator array is well suitable for accurately predicting the performance of the 1-3 piezoelectric composite with non-uniform thickness. The transducer bandwidth is mainly determined by on its thickness variation. The research results can be used as guidelines for the design of the transducer with non-uniform thickness.