隔震结构损伤性能与可靠度研究

提出隔震结构的地震损伤模型，并采用概率密度演化理论分析隔震结构地震损伤指数的概率统计特征，为隔震结构性态目标的量化提供依据。考虑隔震支座的压剪相关性和拉压性能的差异，给出隔震层的损伤指数模型，再利用Park-Ang损伤指数描述上部结构的损伤状况，建立隔震体系的损伤指数模型；将隔震结构简化为双质点模型，采用Bouc-Wen模型和刚度退化的Bouc-Wen模型分别描述隔震层与上部楼层的滞变特性，建立隔震结构的状态方程，应用四阶龙格-库塔方法迭代求解求解出隔震结构的位移反应和滞变耗能，进而求解隔震结构的损伤指数；建立隔震结构损伤指数的概率密度演化方程，求解损伤指数的统计特征和概率密度函数，然后根据极值分布理论计算损伤指数超过不同性能水准的可靠度。本研究为以可靠度为理论基础的隔震结构损伤分析提供了可借鉴的方法。

Research on reliability-based damage performance of base isolated structure

The seismic damage model of base isolated structure is proposed. The stochastic characteristics of damage index of base isolated structure are analyzed by the probability density evolution method. This work provides the basis for performance objective quantification of base isolated structure. The damage index model of the isolation story is proposed by considering the compression-shear correlation and tension-compression difference of isolators. The Park-Ang damage index is used to describe damage status of superstructure. The damage index model of base isolated structure is established. The simplified two masses calculating model of base isolated structure is established. The Bouc-Wen model is used to simulate the isolation layer and the stiffness degradation of Bouc-Wen model is used to simulate the superstructure. The state equation of base isolated structure is established. The displacement response and the hysteresis energy of base isolated structure are iterative solved by four-order Runge-Kutta method. As a result, the damage index of base isolated structure can be got. The probability density evolution equation of base isolated structure is established. The stochastic characteristics and probability density function of damage index are obtained. The reliabilities of damage index not exceed different performance levels are calculated by extreme value distribution theory. The reliabilities of base isolated structure impacted by different yield force ratios and period ratios are also analyzed. This study provides a reference method for performance based seismic design of base isolated structure on basis of reliability theory.