多阻尼比设计反应谱的非平稳地震动场拟合

Multi-damping-ratio design spectra fitting with correlated and non-stationary seismic fields

采用频域调整方法生成与设计反应谱相吻合的地震动,并利用解析迭代方法计算地震动的反应谱,提出了迭代计算的收敛准则。在相关地震动场模拟方法中,将相位差谱的统计模型引入空间相关非平稳地震动场的模拟方法之中,利用快速傅里叶变换技术生成地震动场。将设计反应谱的地震动拟合与非平稳地震动场的合成结合在一起,解决了多阻尼比设计反应谱的非平稳地震动场拟合问题。

The earthquake motion history compatible with design spectra was generated by the spectral matching technique in frequency domain while the spectrum of the motion history was computed by using the analytical iteration method.The convergence criterion of the iterative process was presented here.The empirical model of phase difference spectrum was introduced firstly into the simulation of spatial correlated and non-stationary ground motions.The simulated ground motions were expressed with the power spectra,coherence function and random phase angles generated according to the empirical model of phase difference spectrum,and were generated using discrete Fourier transformation.Combining the design spectral matching technique and the simulation method of seismic fields,the multi-damping-ratio design spectra were compatible with correlated and non-stationary seismic fields.