约束组合梁抗火性能试验研究  

Experimental investigation on fire-resistant behavior of restrained composite beams

作　　者：李国强[1] 王银志[1] 郝坤超[2] 

机构地区：[1]同济大学土木工程学院,上海200092 [2]中国京冶工程技术有限公司,上海201206

出　　处：《自然灾害学报》2007年第6期93-98,共6页Journal of Natural Disasters

基　　金：国家创新研究群体科学基金项目(50321803)

摘　　要：通过利用约束框架对组合梁施加约束,研究了处于结构整体中的组合梁的抗火性能及其在火灾中破坏的过程和特点。试验用了两个足尺试件,分别为简支梁和连续梁。采用一种间接的方法得到了抗火试验中难以测得的组合梁的轴力及弯矩等参数。试验表明:(1)悬链线效应有助于提高组合梁的抗火性能;(2)常温下满足宽厚比要求的钢梁的下翼缘,在火灾下仍会发生屈曲;(3)组合梁的节点设计中应进行轴向承载能力验算;(4)组合梁在火灾中的破坏过程可划分为升温膨胀阶段、跳跃阶段和悬链线阶段。The behavior of restrained beam in actual structure is much different from that of isolated beam because of its high redundance. This paper presents an experimental research on restrained composite beams in fire conducted in the Fire Laboratory at Tongji Univ. A steel frame was designed to supply the restraint to the specimen. Two types of connection were examined with the bottom of the composite beam subjected to standard fire. The force and moment of the composite beam are calculated indirectly through the horizontal and vertical displacement of support. Results of the experiment show： （ 1 ） buckling occurred at the end of bottom flange which would not buckle at normal atmosphere temperature no matter the beam is fixed or simply supported; （2） catenary action enhanced the fire-resistance capacity of the composite beam; （3） high tension may make the connection fracture during the cooling phase; （4） restrained composite beam in fire will experience three stages： expansion stage, leap stage and catenary stage.

关 键 词：组合梁 抗火性能 悬链线效应 试验研究 

分 类 号：TU398[建筑科学—结构工程]