基于随机过程的随机函数解释,发展了一种随机地震动模型。模型包括两个部分,分别是基于理论物理关系的Fourier幅值谱模型和基于经验关系的Fourier相位谱模型。基于拟加速度谱概念建立的幅值谱模型能够反映强震记录的幅值特性,而Fourier相位谱模型则利用累积相位谱的单值连续特性,以线性多项式与三角级数组合的形式给出。模拟记录与实测记录对比结果显示两者不仅在波形结构上相似性良好,而且反应谱层次亦吻合良好。
A stochastic process can be defined as a function with random parameters. Based on these ideas, an original random function for earthquake accelerograms is proposed. The new model contains two parts: one is the model for the Fourier amplitude spectrum, which is obtained from the physical theorem; the other is the model for the Fourier phase spectrum, which is obtained from the empirical theorem. The Fourier amplitude spectrum model (FASM) can be deduced from the theorem of the pseudo - acceleration spectrum. The Fourier phase spectrum model (FPSM) is built on the accumulated phase spectrum and to be composed by linear polynomial and trigono- metric series. Most characters of accelerograms can be reconstructed by the proposed model in the waveform domain as well as at the response spectrum level.