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

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.