基于有限元的悬臂梁式压电换能器的模型辨识

Cantilever Piezoelectric Transducer Model Identification Based on Finite Element Analysis

利用Coventorware软件对悬臂梁式压电换能器进行有限元分析,通过谐响应分析获取了该模型感兴趣频段上离散的幅频和相频数据,然后利用基于倒实频特性与倒虚频特性的最小二乘法进行传递函数参数估计,获得了该换能器的二阶近似传递函数模型。用近似传递函数计算出的系统阻尼比与有限元分析中设定的基本相同,由该传递函数确定的幅频特性曲线和相频特性曲线与仿真数据拟合良好(相对误差约为4%),表明所得传递函数模型与仿真模型是一致的。

The harmonic response analysis of a cantilever piezoelectric transducer was conducted by using finite element analysis software Coventorware and discrete data about amplitude and phase versus frequency in the interesting bandwidth was obtained. Then the least square algorithm parameters of the transfer function model based on the real component and the imaginary component of the reciprocal of the transfer function were estimated, and the second order transfer function of the transducer was derived. The damping ratio resulted from the transfer function approximates the configuration in Coventorware. The amplitude and phase characteristics of the transfer function are in accordance with the simulation data, which indicates that the transfer function agrees with the simulation model.