【摘要】 为了更方便合理地计算地震力,利用单自由度(SDOF)体系弹塑性动力时程分析程序,对反向加载时刚度退化的修正克拉夫滞回模型,计算了四类场地下共370条地震波输入后的结构动力响应,给出了具有不同保证率的弹性强度系数eη谱和地震力折减系数Rμ谱及其计算公式,分析表明这两种谱的特征周期不同.利用两者相除计算不同保证率的弹塑性屈服强度系数yημ谱,并与程序直接计算的弹塑性统计谱进行了比较.发现如果eη谱和Rμ谱采用相同的特征周期TgR谱来归一化,得到的曲线与实际的yημ谱符合得不好,为此最后直接给出了采用加速度谱的特征周期Tga归一化的ηyμ谱.结果表明,四类场地的ηyμ谱变化趋势一致,当T<Tga时,ηyμ谱随着周期T的增大而增大;当T>Tga时,ηyμ谱将随周期T指数下降.更多还原

【Abstract】 Dynamic inelastic response of single degree-of-freedom(SDOF) systems for the modified-Clough hysteretic model with stiffness degradation when subjected to reverse loading was analyzed in order to calculate the seismic force conveniently and rationally,Total 370 earthquake records belonging to four site types were used as excitations.The formula for elastic strength demand factor ηe and the seismic force modification factor Rμ with different probability levels were proposed.The two types of spectra have different characteristic periods.Inelastic yielding strength demand factor ηyμ spectra were calculated for different combinations of η/R and compared to the spectra derived from statistical analysis.If the ηe and the Rμ spectra are normalized by the characteristic periods TgR,the ηyμ spectra are not in good agreement with those derived statistically.Therefore the ηyμ spectra normalized by the characteristic period Tga of acceleration spectra were constructed directly,and the obtained curves were quite similar for the four site types.The ηyμ spectra increase with period T when T<Tga and then descend exponentially with period T.更多还原