组合楼板连续板不同受火工况的有限元分析  

Finite element analysis of continuous composite deck slabs in different fire cases

作　　者：杨秀萍[1] 张怀章[1] 蔡凯武[2] 

机构地区：[1]天津理工大学机械工程学院,天津300384 [2]广东工业大学华立学院机械工程系,广州511325

出　　处：《天津理工大学学报》2009年第6期5-9,共5页Journal of Tianjin University of Technology

基　　金：火灾科学国家重点实验室资助项目(HZ2005-KF05);天津市高等学校科技发展基金(20040505)

摘　　要：采用有限元法对组合楼板连续板在火灾下的结构响应进行模拟,研究了组合楼板三跨连续板在3种不同受火工况下的变形特征、裂纹产生和内力变化规律;分析了负筋长度对连续板火灾行为的影响.结果表明：连续板为超静定结构,受拉钢筋处于低温区,能充分利用其强度,抗火性能优于简支板;连续板的火灾行为与受火工况密切相关;从变形角度看,中跨受火时,耐火性能最好;中、边两邻跨同时受火时,耐火性能最差;支座反力随火灾温度的变化,反映了结构内力的重新分布规律;复杂受火条件下的结构响应一般不能由相应的简单受火条件下结构响应的叠加得到;负筋截断处为塑性铰最容易出现的位置;负筋长度影响楼板的变形形态和变形过程,但对最终挠度影响不大;为提高抗火性能建议负筋长度取为板跨的1/2-2/3.The finite element method was applied to simulate structure responses of continuous composite deck slabs in fire.The regulations of deformation,crack and internal force redistribution of three-span continuous composite deck slabs subjected to fire in different cases were studied.The effect of length of negative bending moment reinforcement on fire behaviour of continuous slab was discussed.The results showed that the continuous composite deck slab was an indeterminate structure and its fire resistance performance was better than that of simple supported slab because the reinforcements in tension were in the low temperature region and their strength could be fully utilized. The fire behaviour of continuous slab related to the fire cases, From the viewpoint of the deformation, the fire duration performance of continuous slab was the best in middle span in fire and the worst in two adjacent spans in fire at the same time. The reaction forces varyied with elevated temperature, which indicated the redistribution of the internal forces. The structure responses in complicated fire case were generally not obtained from superposition of those in simple fire case correspondingly. The endpoints of negative bending moment reinforcement were the positions of plastic hinge appeared easily. The length of negative bending moment reinforcement affected the shape and process of deformation of the slab, it did not do the final deflection. For improving the fire resistance performance of the continuous slab, it was suggested that the length of negative bending moment reinforcement was 1/2 to 2/30f span.

关 键 词：压型钢板-混凝土组合楼板 有限元法 火灾性能 连续板 

分 类 号：TU398[建筑科学—结构工程] TU391