夹心式纵-弯复合振动模式超声换能器的研制

Piezoelectric ceramic sandwiched transducer of ultrasonic longitudinal flexural complex mode vibration

研究了一种新型的夹心式纵－弯复合振动模式压电超声换能器．这种换能器用两套压电陶瓷片分别产生纵振动和弯曲振动．利用波动方程的通解，再加上边界条件，推出了纵振动和弯曲振动的频率方程．由频率方程设计出换能器的尺寸，使两种振动模式工作在同一频率．为验证设计理论，制做了一个频率为１０ｋＨｚ的换能器．实验结果表明，换能器的共振频率与设计值基本吻合．

A piezoelectric ceramic ultrasonic transducer of longitudinal flexural complex mode vibration is studied. Longitudinal mode and flexural mode vibration are produced respectively by placing two sets of ceramics in this transducer. The frequency equations of longitudinal mode and flexural mode vibration are derived, and the length and diameter of the transducer are calculated. The longitudinal mode and flexural mode vibrations of the transducer resonate at the same frequency. A transducer of 10 kHz is made and its resonant frequency is measured. The result shows that the measured frequency is in agreement with the calculated one.