复模态指数函数在正交多项式辨识模态参数算法中的应用

Application of Complex Mode Indicator Function in the Identification of Modal Parameters by Using Orthogonal Polynomials Method

首先介绍了模态指示函数的发展历程和研究现状,重点研究了复模态指示函数(CMIF)的相关理论,并探讨了噪声的存在对复模态指示函数计算结果的影响,之后引入Savitzky-Golay平滑滤波方法对CMIF曲线进行了平滑滤波,最大程度上消除了噪声干扰的影响;然后研究了基于CMIF指示结果的频响函数数据智能抽取算法;最后本文将平滑滤波后的CMIF和基于CMIF的FRF数据智能抽取算法应用在Forsythe正交多项式模态参数辨识算法中,并进行了仿真算例验证,取得了较好的效果。

At first, this paper presents an overview of the latest development in mode indicator functions. Then, this paper researches the complex mode indicator function(CMIF) in detail and verifies its performance considering the interference of noise. As the existence of noise produces a big effect on the performance of the CMIF, this paper smoothes the CMIF by using Savitzky-Golay smoothing filter which can eliminate the interference of noise at the maximal extent. Furthermore, this paper proposes a new extraction algorithm of FRF data which is based on the results of CMIF. Finally, the smoothed CMIF and the FRF extraction algorithm are applied to the identification of modal parameters by using Forsythe orthogonal polynomials method and obtain a good result.