基于广义Morse小波和EWT的移动荷载下结构时变频率识别

Structural time-varying frequency identification under moving load based on generalized Morse wavelet and EWT

提出了基于广义Morse小波和经验小波变换的移动荷载作用下结构时变频率识别方法。首先介绍了经验小波变换技术和广义Morse小波特性,采用经验小波变换对结构响应信号进行分解,对分解得到的不同经验模式成分采用广义Morse小波分析,提取信号小波脊线识别结构瞬时频率。用一个数值算例验证了方法的有效性和精度。随后设计了一个移动小车通过钢板梁的模型试验,采用该方法识别其时变频率并与有限元计算结果进行对比分析,进一步验证方法的效果。

A method based on the empirical wavelet transformation(EWT)and the generalized Morse wavelet was proposed to identify structural time-varying frequency under moving load.Firstly,EWT and the generalized Morse wavelet were introduced.Then a structural response signal was decomposed with EWT,the different empirical mode components decomposed were analyzed with the generalized Morse wavelet to extract signal wavelet ridges,and identify structural instantaneous frequency.Secondly,a numerical example was taken to verify the effectiveness and accuracy of the proposed method.Finally,a model test of a moving car passing through a steel plate beam was designed.The proposed method was adopted to recognize the structural time-varying frequency,and the identified results were compared with those calculated with the finite element method to further verify the effect of the proposed method.