门式钢刚架结构受火力学反应分析  

The Response of Steel Portal Frames Exposed to Localized Fires

作　　者：谢超[1] 杜咏[1] 高庆[1] 

机构地区：[1]南京工业大学土木工程学院,南京211816

出　　处：《防灾减灾工程学报》2015年第1期28-35,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51378259)资助

摘　　要：采用ANSYS有限元分析软件对门式钢刚架结构受火力学反应全过程进行数值模拟,得到门式钢刚架破坏时的临界温度和最不利截面位置,并从结构力学基本理论出发,验证ANSYS数值模拟结果的正确性。研究结果表明,大空间建筑火灾中,影响门式钢刚架结构抗火承载力的控制截面主要是梁柱节点处的梁端截面和梁跨中截面,而且烟气温度场非均匀性将影响结构控制截面的位置,从而影响结构临界温度的变化规律;随着荷载比的减小,临界温度呈升高的趋势;门式钢刚架结构受火破坏模式表明单榀门式钢刚架结构在考虑檩条提供的平面外约束条件下,由于结构冗余度较少,当构件截面发生破坏后,整体结构随即丧失承载力。研究结果可供门式钢刚架结构的抗火设计参考。In order to assess the performance of fire-resistance and operate fire protection, the me- chanical properties of steel portal frames exposed localized fires should be discovered. Based on the numerical analysis of a series of steel portal frames by using ANSYS software, the worst sec- tion location and the critical temperature can be found, which are proved by structural mechanical theory. Parametric analysis provides that the worst section should be located at the beam-column joint or middle span of the beam depending on the temperature distribution for localized fires. Then, the location of the worst section revises the critical temperature. For the given tempera- ture distribution, the critical temperature increases with the decreasing loading ratio. The failure style illustrates that there is no redundant loading capacity for the least redundancy of the steel portal frame. All above conclusions can be employed in fire safety design for steel portal frames.

关 键 词：门式钢刚架 破坏因素 数值模拟 力学分析 倒塌模式 

分 类 号：TU352.5[建筑科学—结构工程]