大震下被动与智能隔震结构动力可靠度的对比

对被动及智能隔震结构在“大震”条件下的动力可靠度进行探讨。将被动及智能隔震体系均取作弹塑性模型,并用退化Bouc-W en滞变模型描述上部结构的恢复力,用非退化Bouc-W en模型描述隔震层的恢复力。采用虚拟激励法计算结构的随机响应,根据我国抗震规范中“大震不倒”的设防目标,采用各层最大层间位移峰值响应和累积滞变耗能构造双参数的随机疲劳累积损伤指数,作为功能状态指标。假定各层失效相关,用串联系统计算体系动力可靠度。通过数值算例,对比了被动隔震、智能隔震与非隔震体系的条件失效概率,从动力可靠度角度显示了智能隔震体系的减震优势。

Comparison of seismic reliability of passive and smart isolated structures under major earthquakes

This paper investigates the dynamic reliability of passive and smart isolated structures under major earthquakes.Both passive and smart isolated structures are assumed to be elasto-plastic,and the Bouc-Wen hysteretic model is adopted to represent the isolator and the degrading Bouc-Wen model is used for the superstructure.The pseudo excitation method(PEM) is employed to calculate the random response of structures.Double damage parameters of maximum story drift and hysteretic energy are adopted as a limit state index according to the requirement of "not collapsing under major earthquake" specified by the seismic design code of China.The dynamic reliability of the structural system is calculated by assuming that the stories are serially connected and that the failure of all the stories is correlated.The conditional failure probability of passive and smart isolated structures is compared with that of the fixed base structures through a numerical example.The advantage of smart isolation in vibration mitigation is exhibited from the view point of dynamic reliability.