摘要
为研究局部火灾引起整体钢结构的初始破坏机理与倒塌机制,对2个平面4跨3层钢框架结构的中柱进行抗火性能试验,通过试验得到受火梁、柱的温度场分布和位移反应的变化规律,通过测力支座得到受火中柱的轴力变化过程。结合有限元分析,研究中柱破坏引起结构倒塌的破坏机理,确定了中柱屈曲温度、中柱破坏温度和结构的破坏温度。研究结果表明:整体结构中受火中柱在高温下发生弱轴方向弯曲破坏,同时也在受保护节点下部钢柱发生局部屈曲破坏;整体结构的初始倒塌机制表现为中柱平面外失稳弯曲的初始破坏引起上部所有约束梁的破坏,局部构件的破坏并不说明整体结构的破坏;竖向荷载水平越大,中柱屈曲温度、破坏温度越低。
To study the initial failure and collapse mechanisms of interior column failure for multi-story steel structures under fire,tests of two full scale steel frame structure were performed. The temperature distribution and displacement response of the column and beam were obtained,and the variation of axial force of the interior column was obtained using the force-measuring bearing. Based on the finite element analysis and test results,collapse mechanism of steel structures induced by the interior heated column was analyzed,and column buckling temperature,column failure temperature,and structural failure temperature were defined. The results show that bending failure occurs in the weak axis direction for the column under high temperature. Local buckling failure occurs at the heated column below the fire-protected joint. Buckling failure of the interior column leads to failure of all the upper connected beams. Failure of a column in a structure does not mean the collapse of the structure. The column buckling temperature and column failure temperature decrease with the increase of the load level.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2015年第2期115-122,共8页
Journal of Building Structures
基金
国家自然科学基金项目(50908006
51278516)
关键词
钢框架
测力支座
抗火试验
破坏温度
初始倒塌机制
steel frame
force-measuring bearing
fire test
failure temperature
initial collapse mechanism
