用于矢量水听器的压电单晶面剪切模式加速度计设计

Design of Piezoelectric Single Crystal Face Shear Mode Accelerometer for Vector Hydrophones

面剪切振动模式产生于[011]极化方向zxt-45°切型的压电单晶,因具有高压电系数、高机械品质因数、高柔顺系数和低串扰效应等优点,故面剪切模式成为小尺寸、高灵敏度压电传感器的理想选择,在矢量水听器中有着良好的应用前景。该文通过分析面剪切模式振动原理,推导了面剪切模式压电加速度计的电压灵敏度表达式。利用有限元分析软件构建面剪切加速度计模型,研究结构参数对面剪切压电加速度计电压灵敏度和谐振频率的影响规律,优化结构尺寸,最终仿真得到面剪切加速度计开路电压灵敏度为389.72 mV/g,工作频带为20 Hz~3 kHz,横向灵敏度小于3.45%。研究结果表明,与传统的剪切式加速度计相比,所设计的面剪切式加速度计在质量块质量降低50%的同时,电压灵敏度提高了11.6%,这为降低水听器的平均密度、提升水声探测性能提供了新思路。

The face shear vibration mode is generated in the piezoelectric single crystal with the zxt-45°cut in the[011]polarization direction.Due to its advantages of high piezoelectric coefficient,high mechanical quality factor,high compliance coefficient and low cross-talk effect,the face shear mode has become an ideal choice for small size,high sensitivity piezoelectric sensors,and has a good application prospect in the vector hydrophones.In this paper,the voltage sensitivity expression of the face shear mode piezoelectric accelerometer is derived by analyzing the vibration principle of the face shear mode.The finite element analysis software was used to establish the face shear accelerometer model,study the influence of structural parameters on the voltage sensitivity and resonance frequency of the face shear piezoelectric accelerometer,and optimize the structure size.The final simulation results show that the open circuit voltage sensitivity of the face shear accelerometer is 389.72 mV/g,the working frequency band is 20 Hz-3 kHz,and the lateral sensitivity is less than 3.45%.The research results show that compared with the traditional shear accelerometer,the designed face shear accelerometer has 11.6%higher voltage sensitivity while the weight of the mass block is reduced by 50%,which provides a new idea for reducing the average density of hydrophones and improving the performance of underwater acoustic detection.