近断层脉冲地震动作用下泛旗帜型滞回模型的等延性位移谱

自复位结构因兼具耗能与残余变形小的特性而受到广泛关注。为了获得此类结构在近断层脉冲地震动作用下的弹塑性位移反应谱，自编了泛旗帜型滞回模型单自由度体系的弹塑性时程分析程序。输入102条脉冲地震波，且每条波作用下的结构分析均考虑40种计算工况，建立了可考虑标准化周期、刚度比、位移延性系数、耗能系数影响的周期标准化弹塑性等延性位移谱。研究结果表明：周期标准化可显著减小位移谱的离散性，刚度比在［0,0.20］区间变化对位移谱的影响很小；位移谱随标准化周期呈现先增大后减小的趋势且最终趋于常值，位移谱峰值对应的标准化周期约为1；位移谱在短周期区间［0,0.7］与位移延性系数呈正相关，其后呈负相关；增加耗能系数可以减小位移，且其在［0,1］区间的位移控制效果较好。

Constant-ductility displacement spectra of generalized flag-shaped hysteretic model subjected to near-fault pulse-like earthquakes

The self-centering structure has been extensively studied for its energy dissipation and minor residual deformation. In order to obtain the elastoplastic displacement spectra of such structures when subjected to near-fault pulse-like earthquakes, the nonlinear time history analysis of single-degree-of-freedom system with the generalized flag-shaped hysteretic model was performed. A total of 102 near-fault pulse-like records were input as seismic excitation, and 40 working conditions were considered for structural analysis under the action of each record. Then, the period-normalized constant-ductility displacement spectra were developed. The influences of normalized period, post-to-pre-yield stiffness ratio, ductility coefficient and the energy dissipation coefficient on the spectra were carefully considered. The results show that the period normalization can effectively reduce the dispersion of the spectra. The post-to-pre-yield stiffness ratio has little effect on the spectra as it varies from 0 to 0.20. With the increasing of the normalized period, the spectra grow larger at first and then decrease gradually to a constant value. The corresponding normalized period to the peak value of spectra approximately equals to 1. The spectra show a positive correlation with the ductility coefficient in the short period range from 0 to 0.7, and then show a negative correlation beyond this range. The value of spectra can be reduced by a larger energy dissipation coefficient. The displacement control for these structures will be more efficient if it lies within the range of 0 to 1.