通过实验模态分析设计阵列式压电模态传感器

Design of modal sensors using PVDF array based on experimental modal analysis approach

提出一种新的基于实验模态分析的阵列式压电模态传感器设计方法。首先利用PVDF阵列进行实验模态分析得到结构的曲率模态,然后直接将曲率模态振型函数在相应测量点的幅值作为加权系数,对结构进行模态滤波,得到各阶模态坐标,并加以实验验证。研究发现,利用该方法设计阵列式压电模态传感器是可行的,而且该方法不需要进行复杂的数值计算,操作简单,模态滤波效果良好,可以很容易推广到二维复杂结构,具有较好的工程应用前景。

By using experimental modal analysis approach,an experimental methodology for design of modal sensors using PVDF array was presented. Firstly,the curvature modal shapes（ the second spatial derivatives of modal shapes） of structures were directly obtained with experimental modal analysis using an array of rectangular PVDF patches regularly arranged on the surface of structures. Then, the amplitudes of the curvature modal shape functions at measurement points were taken as weights of PVDF array. The weighted combinations of the PVDF outputs were proportional to responses of target modes. Other modes were filtered out. Numerical simulation and experimental results showed that the proposed method is effective and easy to operate; furthermore,this method can be extended to twodimensional structures and it has a good prospect of engineering application.