装配式斜撑节点钢框架连续倒塌分析与机理研究*
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(1 湖南大学土木工程学院钢结构研究所， 长沙 410082； 2 湖南科技大学， 湘潭 411201)
［摘要］以某30层装配式斜撑节点钢框架实际工程为例，通过敏感性指标选取关键构件，并采用合理的子结构模型进行连续性倒塌过程数值模拟分析，研究了关键构件失效过程中节点位移及相关构件内力变化情况，并从内力重分布机制以及二道防线的失效模式等方面研究其破坏机理。结果表明：中柱失效后结构二道防线的塑性发展区最先出现在失效层上层与斜撑相连的上弦杆处，该处的塑性继续发展会形成“转动铰下方”的局部重分布机制；斜撑对斜撑域内构件具有良好的保护作用，并能有效地调整中柱失效后结构的内力分布模式。［关键词］斜撑; 斜撑节点钢框架; 连续性倒塌; 动力非线性分析; 关键构件中图分类号：TU312+.3， TU393.3 文献标识码：A 文章编号：1002-848X(2015)17-0054-05
Progressive collapse analysis and mechanism study on prefabricated steel frame structure with inclined brace jointShu Xingping1, Hu Jia1, Yao Yao1, Lu Beirong2(1 Steel Structural Institute of Civil Engineering College, Hunan University, Changsha 410082, China; 2 Hunan University of Science and Technology, Xiangtan 411201, China)
Abstract:Taking a 30-storey prefabricated steel frame structure with inclined brace joints as engineering example, key components were selected through the sensitivity index and rational substructure model was adopted to carry out numerical simulation analysis of progressive collapse process. The joint displacements and internal force changes of the related key components in the process of failure were studied as well as the failure mechanism from perspectives of redistribution mechanism of internal force and the failure modes of second seismic defense line. The results show that the plastic development zone of the second seismic defense line first appears in the upper chord on the upper layer of failure layer connected with the inclined brace after the failure of the middle column. The plastic development will continue to form the partial redistribution mechanism of “rotation hinge-below”. The inclined brace has good protective effect on components in inclined brace domain, and can effectively adjust the internal force distribution mode of the structure after the failure of the column.Keywords: inclined brace; steel frame structure with inclined brace joint; progressive collapse; dynamic nonlinear analysis; key component*国家自然科学基金项目（51278178）。作者简介：舒兴平，教授，博士生导师，Email:shuxingping@sina.com。
