单自由度自复位体系设计能量谱研究

本文对具有旗帜型滞回模型的单自由度自复位体系提出了设计能量谱的构造方法,包括设计输入能量谱和设计滞回耗能比谱。首先按中国规范场地类别选取360条实际强震记录进行时程分析,对影响单自由度自复位体系输入能量谱和滞回耗能比谱的参数,包括地震波类型、滞回模型、阻尼比、延性系数等进行研究。在此基础上分别建议了设计输入能量谱和设计滞回耗能比谱及其曲线参数的确定方法,并与实际强震记录计算结果进行比较。结果表明结构滞回模型对能量谱影响明显;阻尼比和延性系数对输入能量谱的影响在整个周期范围内有显著差异,但均有明显的削峰作用。建议的两种设计能量谱综合考虑了结构参数、地震波参数和中国场地类别的影响,可以较好的拟合实际情况,并对弹塑性单自由度自复位体系在地震作用下的耗能需求做出较准确的估计。

Design energy spectra for self-centering SDOF systems

This paper proposes a procedure for determining design energy spectra for self-centering single-degree-of-freedom(SDOF) systems with a characteristic flag-shaped hysteretic model, including design input energy spectra E_I and design hysteretic energy spectra E_H/E_I. First, nonlinear dynamic time history analyses are conducted using a total of 360 ground motion records selected according to the Chinese code. Then, the results are used to establish the relationship of input energy spectra and hysteretic energy spectra with critical parameters, such as ground motion types, hysteretic models, the damping ratio and the ductility factor. Based on this, two kinds of design energy spectra and relevant parameters are suggested, and compared with results from nonlinear dynamic time history analyses. The results indicate that hysteretic models play an important role in energy spectra. The damping ratio and ductility factor have different influences on the input energy spectra through the entire period, yet they both decrease peak values of the input energy spectra. The proposed design energy spectra consider the influence of structural parameters, ground motion factors and the classification of soil by the Chinese code. They can be adopted to predict hysteretic energy demand for self-centering SDOF systems.