基于希尔伯特-黄变换的汶川地震记录分析

Analysis of Acceleration Time Records in Wenchuan Earthquake Based on Hilbert-Huang Transform

利用HHT方法对6个台站的汶川8.0级地震加速度记录进行EMD分解,进而对地震波输入结构的总能量进行分解,得到地震动能量在IMF分量之间的分布关系。同时通过对各分量边际能量谱的分析,可以从另一方面得到地震波的频谱特性,边际能量谱峰值频率与地震波傅立叶谱的卓越频率相同,边际能量谱也可以作为一种估算震动卓越周期的方法。

Using the Hilbert-Huang Transform, acceleration time histories recorded by 6 stations in Wenchuan M8.0 earthquake are decomposed into several Intrinsic Mode Function components by Empirical Mode Decomposition. The total energy of structure inputted by seismic wave is decomposed to get the distribution relation of the ground motion energy in the different IMF component. By analysis of marginal energy spectrum of each IMF component, we can obtain the spectral characteristics of seismic wave. The frequency of marginal energy spectrum peak is the same as the predominant period of the Fourier spectrum of seismic wave, so it can also be used as the way to estimate the predominant period of vibration.