Luhuo MS5. 3 earthquake occurred in Sichuan on April 10, 2011. In this paper three components of acceleration time history records acquired by different stations with different epicenter distances are selected. Aimed at the problem in HHT method in the decomposition of EMD which is present common way for extracting the signal time-frequency characteristics, a EEMD method is used and the energy calculation and time-frequency analysis on acceleration records are made. The method can not only effectively restrain the problem occurred in EMD decomposition process,but also can extract record's time-frequency characteristics and the energy concentration distribution bands. Comparative study among this method and Fourier transform and wavelet analysis is made. The validity and practicability of the method are proved in dealing with the unsmooth, nonlinear strong signal, and has a good prospect in earthquake data processing area.%2011年4月10日四川炉霍发生Ms5.3地震.本文选取了此次地震中不同震中距的台站所获取的三分量加速度时程记录,针对目前EMD分解的HHT方法存在的模态混叠问题,采用了一种基于EEMD分解提取信号时频特性的方法,对加速度记录进行能量计算和时频分析发现,该方法不但有效抑制了以往EMD分解过程中所出现的模态混叠问题,而且还较好地提取到记录的时频特性和能量集中分布的时频段.并与Fourier变换、小波分析进行了对比研究证明了该方法在处理非平稳、非线性强震信号中的有效性和实用性,在强震数据处理领域有着较好的应用前景.
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