基于HHT方法的非平稳人工地震动模拟
|
摘要
由Hilbert-Huang变换(HHT)得到实际地震动的时变渐进功率谱,利用渐进功率谱和三角级数法进行人工地震动的合成。与传统方法中先生成平稳人工波,再乘以强度调制函数进行非平稳化相比,文中利用渐进功率谱生成的人工波能够反映地震波能量在时频平面上的分布,它不仅具有强度非平稳性,而且也具有频率非平稳性,更符合实际情况。同时将HHT方法和求解渐进功率谱时常用的短时傅里叶变换(STFT)和多重滤波法进行比较,表明具有自适应性的HHT方法能更快速、准确地估计地震动渐进谱,时频分辨率更高,更适合于人工地震动的模拟。
The artificial seismic ground motions have been synthesized by the use of trigonometric series and time varying power spectrum,which is estimated by the Hilbert-Huang Transform(HHT) theory.The method proposed is different from the traditional procedure,which synthesizes non-stationary artificial seismic ground motion by strength modulation function.It can reflect the energy contribution characteristics on the time-frequency plane and the artificial seismic ground motion is non-stationary both in time and frequency domains.At the same time,the HHT is compared with short-time Fourier transform(STFT) and multi-filter,the comparison results demonstrate that the HHT has higher time-frequency resolution capability and greater advantage in speed and accuracy for estimating the time varying power spectrum.It's more suitable to simulate artificial seismic ground motion.
The artificial seismic ground motions have been synthesized by the use of trigonometric series and time varying power spectrum,which is estimated by the Hilbert-Huang Transform(HHT) theory.The method proposed is different from the traditional procedure,which synthesizes non-stationary artificial seismic ground motion by strength modulation function.It can reflect the energy contribution characteristics on the time-frequency plane and the artificial seismic ground motion is non-stationary both in time and frequency domains.At the same time,the HHT is compared with short-time Fourier transform(STFT) and multi-filter,the comparison results demonstrate that the HHT has higher time-frequency resolution capability and greater advantage in speed and accuracy for estimating the time varying power spectrum.It's more suitable to simulate artificial seismic ground motion.
引文
[1]胡聿贤.地震工程学[M].北京:地震出版社,1988.
[2]王君杰,周晶.地震动频谱非平稳性对结构非线性反应的影响[J].地震工程与工程振动,1997,17(2):16-20.
[3]Priestley M B.Power spectral analysis of non-stationary random processes[J].Journal of Sound and Vibration,1967,6(1):86-97.
[4]梁建文.非平稳地震动过程模拟方法I[J].地震学报,2005,27(2):213-238.
[5]Kameda H.Evolutionary spectra of seismogram by multifilter[J].Journal of the Engineering Mechanics Division,ASCE,1975,101(6):787-801.
[6]Huang N E,Shen Z,Long S R,et al.The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series a-nalysis[J].Proc R Soc Lond A,1998,454:903-995.
[7]胡灿阳,陈清军.基于HHT法的地震地面运动局部谱密度估计[J].振动与冲击,2007,26(10):126-131.
[8]Husid R L.Analisis de terremotos:analisis general[J].Revista del ID1EM,Santiago Chile,1969,8(1):21-42.
[2]王君杰,周晶.地震动频谱非平稳性对结构非线性反应的影响[J].地震工程与工程振动,1997,17(2):16-20.
[3]Priestley M B.Power spectral analysis of non-stationary random processes[J].Journal of Sound and Vibration,1967,6(1):86-97.
[4]梁建文.非平稳地震动过程模拟方法I[J].地震学报,2005,27(2):213-238.
[5]Kameda H.Evolutionary spectra of seismogram by multifilter[J].Journal of the Engineering Mechanics Division,ASCE,1975,101(6):787-801.
[6]Huang N E,Shen Z,Long S R,et al.The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series a-nalysis[J].Proc R Soc Lond A,1998,454:903-995.
[7]胡灿阳,陈清军.基于HHT法的地震地面运动局部谱密度估计[J].振动与冲击,2007,26(10):126-131.
[8]Husid R L.Analisis de terremotos:analisis general[J].Revista del ID1EM,Santiago Chile,1969,8(1):21-42.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心