基于多物理场耦合的夹心式压电换能器优化设计

Design and Optimization of Sandwich Piezoelectric Transducer Based on Comsol Multiphysics

针对传统解析法在压电换能器设计中存在适用范围窄、计算繁琐以及结果不精确等缺点,提出了基于Comsol的换能器优化设计。为得到夹心式压电换能器的初步尺寸,笔者基于一维细棒振动和Mason等效电路理论得到了换能器的频率方程和前后振速比公式;结合实际工况选定材料后利用1st Opt对前盖板的隐函数进行求解,设计了换能器的结构参数;基于Comsol Multiphysics的压电耦合模块对设计的换能器进行动力学仿真研究,得到了换能器的特征频率、相应振型以及正反谐振频率、基频频率和最高电导值,从而获得了换能器的节面高度、品质因数以及动态电阻等参数。模拟结果得出换能器相应参数与设计值有一定误差,可利用Comsol优化模块对前后盖板尺寸进行修正。结果表明改进后的换能器频率与设计值误差为0.067%,且节面位于陶瓷晶堆中间位置。该方法可以有效提高换能器的使用性能和缩短研制周期,对压电换能器的优化设计有一定的参考意义。

Aiming at the shortcomings of traditional analytical methods in designing piezoelectric transducers,such as narrow application range,complicated calculation and inaccurate results,the optimal design of transducer based on Comsol is proposed. In order to obtain the preliminary dimensions of the sandwich piezoelectric transducer,the frequency equation and the velocity ratio formula of the transducer were obtained based on the one-dimensional fine rod vibration and the Mason equivalent circuit theory. Combined with the actual working conditions,the hidden function of the front cover plate was solved by 1 st Opt and the structural parameters of the transducer were designed. The dynamic simulation of the designed transducer was studied based on the piezoelectric coupling module of Comsol Multiphysics.The characteristic frequency and the corresponding vibration mode,the positive and negative resonant frequency,the fundamental frequency and the highest conductance value were calculated, thereby obtaining the position of the transducer＇s nodal section,quality factor and dynamic resistance. The simulation results show the certain errors between the corresponding parameters of transducer and the design value. The size of the front and rear cover plate was corrected based on the Comsol optimization module. The results show that the error of the improved transducer frequency and the design value is 0. 067%,and the nodal plane is located in the middle position of the ceramic crystal pile. The method can effectively improve the performance and shorten the development cycle of transducers, which is of guiding significance to the optimal design of piezoelectric transducers.