Hilbert-Huang变换在桥梁振动分析中的应用

Application of Hilbert-Huang Transform to theVibration Analysis of Bridges

提出将Hilbert Huang 变换的信号处理方法应用于桥梁振动分析中。此方法是通过经验模态分解(EMD)将一复杂的原始数据序列分解成一组本征模函数(IMF)和一个残余项,然后再对每一个IMF进行Hil bert变换。这样所得到的信号幅度和瞬时频率都是时间的函数,即获得了幅度的频率时间分布,称为Hilbert Huang幅度谱,进而得到Hilbert边界谱。文中利用Hilbert Huang变换对南京桥有列车通过时的实测加速度响应进行了处理与分析,结果表明该方法可行、有效。

The signal processing method of Hilbert-Huang transform is applied in the vibration analysis of bridges. The complicated original data set is decomposed into a series of intrinsic mode functions (IMF) and a residue by the empirical mode decomposition (EMD). Each IMF is transformed into signal amplitudes and instantaneous frequencies as the functions of time by the Hilbert transform method. Thus, the frequency-time distribution of the amplitude designated as the Hilbert-Huang amplitude spectrum H(ω,t) and accordingly the marginal Hilbert spectrum H(ω,t) are obtained. The measured acceleration responses of the Nanjing Yangtze River Bridge under train passing are processed by Hilbert-Huang transform. Results show the method is effective and practicable.