基于随机Fourier谱的地震动合成研究
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摘要
本文基于与物理随机模型相对应的随机Fourier谱,通过对地震动非平稳性及其所受影响机制的分析,建立了非平稳地震动合成的新方法。通过引入基本相位差谱,并将初始相角视为随机变量,以相位差谱的分布特性、随机地震动的统计特征以及对结构随机反应的影响为原则,利用计算机程序生成相位差谱,提出了基于随机Fourier谱的合成地震动方法。同时,利用快速FFT技术提高合成精度。根据本文提出的合成方法获得的地震动具有非平稳特性,将为后续研究工作提供合理的地震动加速度时程。
Based on the random Fourier spectra corresponding to the physical random earthquake model and considering the character of seismic non-stationarity and the influencing mechanism,this paper proposes a new approach to synthesize the earthquake motion presenting non-stationarity.The basic phase angle difference spectrum is led in and the initial phase angle is regarded as a random variable.The distribution characteristics of the phase angle difference spectrum,the statistical characteristics of random ground motion and the effects on structural stochastic response are the judgment strategy.Utilizing the computation procedure to produce the phase angle difference spectra,a synthetic method is proposed on the basis of the random Fourier spectra.Simultaneously,the fast FFT technique is applied to improve the synthetic accuracy.The proposed method is capable of achieving non-stationary earthquake motion,which would provide reasonable seismic acceleration for succeeding research work.
Based on the random Fourier spectra corresponding to the physical random earthquake model and considering the character of seismic non-stationarity and the influencing mechanism,this paper proposes a new approach to synthesize the earthquake motion presenting non-stationarity.The basic phase angle difference spectrum is led in and the initial phase angle is regarded as a random variable.The distribution characteristics of the phase angle difference spectrum,the statistical characteristics of random ground motion and the effects on structural stochastic response are the judgment strategy.Utilizing the computation procedure to produce the phase angle difference spectra,a synthetic method is proposed on the basis of the random Fourier spectra.Simultaneously,the fast FFT technique is applied to improve the synthetic accuracy.The proposed method is capable of achieving non-stationary earthquake motion,which would provide reasonable seismic acceleration for succeeding research work.
引文
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[3]朱昱,冯启民.地震加速度相位差谱分布的数字特征[J].地震工程与工程振动,1993,13(2):30-37.
[4]金星,廖振鹏.地震动强度包线函数的理论研究[J].地震学报,1994,16(4):519-525.
[5]赵凤新,胡聿贤.地震动非平稳性与幅值谱和相位差谱的关系[J].地震工程与工程振动,1994,14(2):1-6.
[6]李杰,艾晓秋.基于物理的随机地震动模型研究[J].地震工程与工程振动,2006,30(5):21-26.
[7]胡聿贤.地震工程学[M].2版,北京:地震出版社,2006.
[8]李杰,李国强.地震工程学导论[M].北京:地震出版社,1992.
[9]大崎顺彦.振动理论[M].谢礼立,等译.北京:地震出版社,1990.
[10]戴诗亮.随机振动试验技术[M].北京:清华大学出版社,1984.
[11]艾晓秋.基于随机地震动模型的地下管线地震反应及抗震可靠度研究[D].上海:同济大学,2005.
[2]Ohaski Y.On the significance of phase content in earthquake ground motions[J].Earthquake Engineering and Structural Dynamics,1979,17(4):427-439.
[3]朱昱,冯启民.地震加速度相位差谱分布的数字特征[J].地震工程与工程振动,1993,13(2):30-37.
[4]金星,廖振鹏.地震动强度包线函数的理论研究[J].地震学报,1994,16(4):519-525.
[5]赵凤新,胡聿贤.地震动非平稳性与幅值谱和相位差谱的关系[J].地震工程与工程振动,1994,14(2):1-6.
[6]李杰,艾晓秋.基于物理的随机地震动模型研究[J].地震工程与工程振动,2006,30(5):21-26.
[7]胡聿贤.地震工程学[M].2版,北京:地震出版社,2006.
[8]李杰,李国强.地震工程学导论[M].北京:地震出版社,1992.
[9]大崎顺彦.振动理论[M].谢礼立,等译.北京:地震出版社,1990.
[10]戴诗亮.随机振动试验技术[M].北京:清华大学出版社,1984.
[11]艾晓秋.基于随机地震动模型的地下管线地震反应及抗震可靠度研究[D].上海:同济大学,2005.
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