火灾下张弦梁结构的性能分析(英文)  

Performance of Beam String Structure under fire

作　　者：薛素铎[1] 何祖彦[1] 李雄彦[1] 

机构地区：[1]北京工业大学空间结构研究中心,北京100124

出　　处：《空间结构》2011年第2期90-96,共7页Spatial Structures

基　　金：Project supported by Natural Science Foundation of Beijing(8082004);National Academic Innovation Teamand Excellent Service Teamfor Beijing

摘　　要：基于实用大空间火灾空气温升模型和张弦梁结构三维整体有限元模型,对火灾下整体结构的抗火性能进行了模拟分析.研究对比了不同火源面积和高度下结构的温度场分布、位移和应力特征、钢索的应力变化和结构破坏模式,得到了不同火灾下张弦梁结构的极限耐火时间.分析结果表明:在火灾作用下由于张弦梁结构局部构件变形过大不能继续承载,导致整体结构失稳和倒塌;结构的抗火薄弱区域位于结构中心附近,结构变形不对称;火灾下引起张弦梁结构破坏的主要因素为较大的初始应力以及高温下结构刚度和强度的降低.Base on the whole three-dimension utility empirical formula of temperature elevation in large space and the al finite element model of Beam String Structure, the fire-resistant performance of the whole structure is studied. The pre-stress of strings, temperature field, displacement and stress characteristics, and failure modes of the structures under different fire areas and heights are analyzed. The ultimate fire-resistant durations of Beam String Structure under different fires are obtained. The results show that. the Beam String Structure can not bear any loads due to the large local deformation, which leads to instability and collapse of the whole structure. The weak area of the structure is near the centre and the structural deformation is asymmetric. The major factors contributing to the failure of BSS are the larger initial stress and the degradation of the strength and stiffness of structural member under high temperature.

关 键 词：抗火 张弦梁结构 非线性有限元分析 性能 火灾 

分 类 号：TU352.5[建筑科学—结构工程]