Q690高强钢梁火灾后承载性能研究  

The Bearing Capacity of Q690 High-Strength Steel Beams After Fire

作　　者：郭小农[1] 宗绍晗 于孟同 徐航 GUO Xiaonong;ZONG Shaohan;YU Mengtong;XU Hang(College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《建筑钢结构进展》2021年第11期103-111,共9页Progress in Steel Building Structures

基　　金：国家重点研发计划(2017YFC0805006)。

摘　　要：为探究Q690高强钢梁火灾后的破坏模式和承载性能,对6根经历650℃高温加载后自然冷却的Q690高强钢梁进行了试验研究。试验结果表明,残余变形对火灾后Q690钢梁的破坏模式和极限承载力均有显著影响;Q690高强钢加热到650℃后自然冷却,其材料性能几乎无变化,仅屈服强度略有降低。在试验的基础上,建立有限元模型并完成校准,进行大规模参数分析,拟合得到火灾后高强钢梁的整体失稳承载力计算公式。拟合公式与规范计算结果和试验数据的对比表明,提出的公式具有足够的精度、合理性和安全性。In order to study the failure mode and bearing capacity of Q690 high-strength steel beams after fire,six Q690 high-strength steel beams cooled to room temperature naturally from 650℃are tested.The test results show that the residual deformation has a significant impact on the failure mode and ultimate bearing capacity of Q690 post-fire steel beams.Besides,for natural cooling Q690 high-strength steel after experiencing 650℃,its material properties almost remain the same,only the yield strength is slightly reduced.Based on the tests,finite element models are built to calibrate test results.To propose the calculation formula of the overall instability bearing capacity of high-strength steel beams after fire,a large number of parameter analysis is carried out.The comparison of the fitting formula with the standard calculation results and test data show that the proposed formula has a good accuracy,rationality and safety.

关 键 词：Q690高强钢梁 火灾后力学性能 整体弯扭失稳 实用计算公式 试验研究 

分 类 号：TU391[建筑科学—结构工程]