基于小波变换的车门运行模态分析

Operational modal analysis for vehicle door based on wavelet transform

高速列车车门是评价高速列车安全性的一个很重要的部件,它对高速列车的密封性及噪声控制有很关键的作用。模态分析是结构动态设计,振动和噪声控制及设备故障诊断的重要方法。传统的传递函数模态分析方法的特点是同时利用激励和响应信号进行参数识别,而基于环境激励下的模态参数识别方法仅根据系统的响应就可以进行参数识别。其中,基于小波变换的模态分析方法非常有前景,它利用其良好的时频分辨能力以及带通滤波性质可以使系统自动解耦,然后从自由振动信号的小波变换谱图的小波脊线出发识别模态参数。本文利用基于小波分析的运行模态分析方法,对高速列车车门进行模态参数识别,效果良好。

The door in high-speed trans is an important component for evaluating the safety and it effects on the sealing and the noise control. Modal analysis is a significant method for structural design, vibration control and fault diagnosis. Traditional modal analysis methods based on transmission function has characteristics of using excitation signal and response signal for modal recognition. However, modal parameters recognition methods based on natural excitation only use the response from the system. Among different methods, wavelet transform based method is very promising because of its good time frequency property and band-pass filtering for automatically decoupling of the system. Then the modal parameters could be recognized by the wavelet ridges of the map from free vibration signal after wavelet transform. The wavelet-based modal analysis method is presented for the door in high-speed trains and the result is very satisfactory