节点域承载力对半刚性钢框架地震易损性影响研究

Seismic Fragility Analysis of Semi-rigid Steel Frame Considering Panel Zone Performance

目的 通过考察节点域承载力变化与地震易损性曲线间的关系,获得半刚性钢框架地震易损性曲线,量化节点域屈服承载力对半刚性钢框架地震易损性的影响。方法 采用OpenSEES抗震分析软件建立以节点域承载力比为主要参数的半刚性钢框架模型,通过地震需求分析和抗震能力分析,绘制不同节点域屈服承载力比(0.5~1.0)对应的半刚性钢框架地震易损性曲线。结果 节点域屈服承载力比的取值为0.7时,半刚性钢框架地震易损性曲线在四种极限状态下均小于其他半刚性钢框架,且形成包络趋势。结论 在水平地震作用下,允许节点域屈服,可显著降低钢框架的失效概率,结构的抗震性能也得到了明显改善;节点域屈服承载力比取0.7时,结构抗震性改善效果最显著。

The seismic fragility curve of semi-rigid steel frame is obtained by investigating the relationship between the load bearing capacity of panel zone and the seismic vulnerability curve,and the influence of the yield load bearing capacity ratio of panel zone on the semi-rigid steel frame vulnerability is quantified.OpenSEES seismic analysis software is used to establish the semi-rigid steel frame model with the load bearing capacity of panel zone as the main parameter.According to the seismic demand analysis and seismic capacity analysis,the seismic vulnerability curve of the steel frame with yield load bearing capacity ratio(0.5~1.0)in different panel zone is plotted.The fragility curves of the semi-rigid steel frames with a value of 0.7 is smaller than that of the semi-rigid steel frame with other values under the four limit states,and forms an envelope trend.Under the action of horizontal seismic,allowing the yield of the panel zone can significantly reduce the failure probability,and the seismic performance of the structure has also been significantly improved.The improvement effect is most significant when the panel zone yield bearing capacity ratio is 0.7.