【摘要】 基于Fourier变换的时频域信息等价性,在频域内建立了强震地面运动的物理模型.地震动的频域物理模型分为2个部分,即基于理论物理关系的Fourier幅值谱模型和基于经验物理关系的Fourier相位谱模型.以单质点体系运动方程为基础的Fourier幅值谱模型反映了强震记录的幅值特性;以相位差分布为基础的Fourier相位谱模型以确定性的显式形式建立了相角与频率的映射关系,能较好地反映原始记录的波形结构.合成的人工波与实际强震记录对比,证明了模型的正确性.更多还原

【Abstract】 Fourier transform can shift a signal in time domain to the counterpart in frequence domain,and a physical model for strong ground motion in frequence domain is established.The new model contains two parts: one is the model for the Fourier Amplitude Spectrum,which is obtained on the basis of physical theorem;the other is the model for Fourier Phase Spectrum,which is obtained on the basis of empirical theorem.The Fourier Amplitude Spectrum Model(FASM) based on motion equation of single degree freedom system reflects most characters of amplitude spectrum of recorded accelerogram.The Fourier Phase Spectrum Model(FPSM) is built on the similarity between envelop of the recorded time history and its phase difference distribution.Function between phase and frequence is simplified in an explicit way.The synthesized accelerogram obtained from the phase spectrum model is similar to the recorded one.The model is justified by the recorded accelerograms.更多还原