弹塑性SDOF系统的地震输入能量谱

以4种场地土条件下40条强震记录为输入,分析了弹塑性单自由度(Single Degree of Freedom,SDOF)系统的地震输入能量谱,并对地震动强度和SDOF系统参数对地震输入能量谱的影响进行了研究。结果表明:能量谱峰值主要由地震动强度决定,阻尼比和延性系数有很大影响。在长周期范围,延性系数一定时,随着阻尼比的增大,能量谱值也有所增大;随延性系数增大,能量谱值随阻尼比增加而增大的趋势有所减缓。采用归一化方法,根据能量谱的特征建议了简化三段式地震输入能量谱,并根据能量谱分析结果的统计,建议了弹塑性SDOF系统能量谱峰值和能量谱曲线参数的确定方法。

EARTHQUAKE INPUT ENERGY SPRCTRUM FOR INELASTIC SDOF SYSTEMS

The earthquake input energy spectrum for inelastic single degree of freedom (SDOF) systems with various damping ratio and ductility factor subjected to 40 earthquake records of 4 site types is studied. The influence of parameters, including the damping ratio and ductility factor of SDOF systems and the intensity of ground motions, on the input energy spectrum is investigated. The results indicate that the peak value of the input energy spectrum mainly depends on the intensity of ground motion, damping ratio and ductility factor. In the long period range, input energy spectrum increases with damping ratio and decreases with ductility factor. With the normalized input energy spectrum method, the input energy spectrum is simplified into three portions as a function of the vibration period of the SDOF systems. Finally, based on statistical analysis of the normalized spectrum, the parameters of the input energy spectrum are suggested.