小波变换在人造地震动拟合中的应用

The Application Study of Wavelet Transform in Generation of Artificial Earthquake

首先采用小波变换将已有的地震动记录信号以小波技术的方式精确表示,再用Mallat算法对其进行正交和分解,从而将地震加速度过程的频率区间划分成紧相邻的不同频带;然后通过变化振幅进行调整各频带的频率组成,使调整过的地震动的反应谱能很好地与场地设计反应谱拟合。这符合时程分析法选择地震动的要求,即所选的地震动要拟合设计反应谱。最后采用一数值模拟案例对该方法进行验证。结果表明,基于小波变换的地震动调整方法是行之有效的,可以为工程和研究提供理论参考。

Firstly,by the way of wavelet transform,the existing ground motion records are precisely defined in terms of wavelet technology and applied it with orthogonal and decomposition by Mallat Algorithm.So that the frequency interval of earthquake acceleration process can be divided into closely neighboring different frequency.The content of each frequency can be adjusted on changes amplitude to meet well the modified ground motion response spectrum with the site designing response spectrum.It corresponds to the demand choosing vibration in time-history analysis,which is the selected ground motion fits designing response spectrum.Finally a numerical simulation example will be used to verify this method.The results show that ground motion adjustment method based on wavelet transform is effective in use and can provide a theoretical reference for engineering and research.