基于小波分析的斜拉索振动频率识别

Identification of Vibration Frequency of Stayed Cable Based on Wavelet Analysis

为了识别跨海斜拉桥拉索在外部因素作用下的振动频率,依托位于海域环境下的某跨海大桥健康监测系统,基于实测数据,采用了小波分析分别对20根斜拉索振的动信号进行分解及重构,再对重构信号进行频谱分析得到了斜拉索振动频率。结果表明:小波变换非常适合对斜拉索振动这类含有稳态和非稳态成份的信号进行时频分析;不同尺度的小波重构信息及频谱图能很好的反应斜拉索的振动特征;应用小波频谱对信号进行处理以及采用峰值拾取法能够精确的识别斜拉索的频率。以上利用小波分析对斜拉索振动频率的识别能为将来斜拉桥设计提供重要参考。

In order to identify the vibration frequency of cable-stayed bridge under the action of external factors,wavelet analysis is used to decompose and reconstruct the dynamic signals of 20 cables respectively based on the health monitoring system of a sea crossing bridge located in the sea environment.And then the frequency spectrum analysis of the reconstructed signals is used to obtain the vibration frequency of cable-stayed bridge.The results show that:wavelet transform is very suitable for the time-frequency analysis of cable vibration,which contains steady and unsteady components;different scales of wavelet reconstruction information and spectrum analysis can reflect the vibration characteristics of cable well;the application of wavelet spectrum to signal processing and peak pick-up method can accurately identify the frequency of cable.The above wavelet analysis can provide important reference for the design of cable-stayed bridge in the future.