运行模态分析中固有模态和谐波模态区分方法研究

摘要：在机械领域存在大量旋转机械，这使得输入激励并不满足运行模态分析（OMA）要求的均值白噪声激励条件。通过对随机信号和谐波信号统计特性的分析，提出一种简单有效的识别响应信号中周期强迫响应的方法，使OMA适用于含有谐波激励的情况，对一块由偏心电机激励的钢板进行了运行模态试验和锤击法传统模态试验，应用该方法成功识别出响应信号中的周期响应成份，通过两种试验结果验证了方法有效性，为OMA中虚假模态的辨别提供了一种新思路。

Modes in operational modal analysis

Abstract:There are lots of rotating machines in mechanical engineering field,which make input excitations don't meet the requirement of operational modal analysis(OMA).A simple and effective method of distinguishing the forced harmonic resonse from the measured vibration signal was presented through analysis of atatistical properties of stochastic signal and harmonic signal.This made OMA applicable to the situation existing harmonic excitation.An OMA and an experimental modal andlysis of a steel plate excited by a motor were carried out the harmonic components were succcessfully separated from the overall response with the proposed method.The comparison of the two experiment results proved the effectiveness of this method which provides a new way to distinguish the pseudo modes in an OMA.