(1 天津大学建筑工程学院， 天津 300072；2 天津大学滨海土木工程结构与安全教育部重点实验室， 天津 300072)

［摘要］为研究梁柱节点转动刚度对结构抗连续倒塌性能的影响，建立平面钢框架模型，并在模型中加入转动弹簧以模拟节点转动刚度。分别对不考虑节点刚度退化的刚接和线性节点模型以及考虑节点刚度退化的非线性节点模型进行数值分析。结果表明：考虑节点刚度退化会使动力放大系数增大；结构在弹性状态下，动力放大系数维持在2-0左右，不考虑节点刚度退化模型可用于连续倒塌分析；结构在塑性状态下，动力放大系数随节点转动刚度与需求能力比（DCR）的增大而减小，不考虑节点刚度退化模型不宜用于连续倒塌分析；随着节点转动刚度的增大，节点耗能占结构总耗能比例减小，梁耗能比例增加。因此建议当节点转动刚度较小时增加节点的变形能力以提高结构的抗连续倒塌性能，反之增加梁的变形能力。

［关键词］节点转动刚度；  连续倒塌； 钢框架； 动力放大系数； 耗能

中图分类号：TU391文献标识码：A文章编号：1002-848X(2017)16-0009-05

Research on progressive collapse resistance performance of steel frame considering beam-to-column joint rotational stiffness

Liu Shipeng1， Liu Mingjie1， Lu Yan1,2， Zhao Yifeng1

（1 School of Civil Engineering， Tianjin University， Tianjin 300072，  China；   2 Key Laboratory of Coast Civil Structure Safety, Ministry of Education, Tianjin University, Tianjin 300072, China）

Abstract:The plane steel frame model was established to study the influence of beam-to-column joint rotational stiffness on the structural progressive collapse resistance performance. The rotational spring element was used in the model to simulate joint rotational stiffness. Numerical analyses were made on the rigid model and linear joint model without considering joint stiffness degradation and the nonlinear joint model considering joint stiffness degradation. The analytical results show that the dynamic magnification factor increases if joint stiffness degradation is considered. The dynamic magnification factor remains at about 2-0 and the model without considering joint stiffness degradation can be adopted for the progressive collapse analysis when the structure is in the elastic state. The dynamic magnification factor decreases with the increase of rotational stiffness and Demand-Capacity Ratio (DCR)  and the model  without considering joint stiffness degradation can not be adopted for the progressive collapse analysis during the plastic state. With the increase of joint rotational stiffness, the ratio of joint energy dissipation to total energy dissipation is decreased, while that of beam is increased. Therefore, it is suggested that the joint deformation ability should be reinforced to improve the structural progressive collapse resistance performance when joint rotational stiffness is decreased, otherwise the beam deformation ability should be reinforced.

Keywords:joint rotational stiffness; progressive collapse; steel frame; dynamic magnification factor; energy dissipation

*天津市城乡建设和交通委员会建设科技项目（2013-35），国家自然科学基金面上项目（51178307）。

通讯作者：芦燕，博士，讲师，Email: yanlu86@tju.edu.cn。