基于动力可靠度的隔震结构参数模糊优化

分别选取Bouc—Wen和退化Bouc—Wen模型描述隔震层及上部结构滞变回复力，采用虚拟激励法进行隔震结构随机响应分析。用各层最大层间位移响应和累计疲劳损伤指数建立双参数的功能状态方程，用一次二阶矩理论计算隔震结构失效概率。选用一个隔震框架作为数值算例，探讨了低频过滤器、隔震阻尼比和隔震刚度对隔震结构各子系统条件失效概率的影响。建立了隔震结构参数多目标优化模型，用失效概率确定单因素评判的隶属度，并采用最大隶属度法对隔震参数进行模糊优化。

Fuzzy optimization of isolation parameters based on dynamic reliability

This paper derives fuzzy optimization model for selecting optimum stiffness and damping ratio of base isolated structure from the view point of dynamic reliability. With the isolation system and superstructure represented by Bouc-Wen and degrading Bouc-Wen hysteretic model, respectively, the random response of the isolated structure is analyzed by pseudo-excitation method. Using double parameters of ultimate story drift and hysteretic energy, function equation is established, and failure probability is obtained based on FORM. A 7-story isolated RC frame is used as numerical example, and the effect of low-frequency filter, isolation damping ratio and stiffness on the system failure probability is discussed. A range of optimum stiffness and damping ratio is suggested based on vector minimization of failure probability of both super structure and isolation system.