摘要
目的研究方钢管约束钢管混凝土柱在三面受火情况下的耐火极限,为其抗火设计提供依据.方法在合理选取材料属性与边界条件的前提下,利用ABAQUS有限元软件建立三面受火的方钢管约束钢筋混凝土柱的数值模型;在模型合理基础上,分析荷载比、长细比、截面尺寸、荷载偏心率和含钢率等参数对构件耐火极限的影响.结果荷载比和长细比对结构的耐火极限具有更显著的影响,耐火极限随荷载比和长细比的增大而减小;构件荷载比由0.4增至0.6,其耐火极限下降54.60%;长细比由20升至40,耐火极限下降25.68%;当含钢率由2%上升至4%时,构件的耐火极限上升10.94%;荷载偏心率对结构的耐火极限影响较为复杂,构件耐火极限在e/i=-0.2时极限承载力迅速提高.结论减小构件长细比,并增大含钢率,可有效提高构件耐火极限.
The fire resistance of square steel tube confined reinforced concrete column under three-side fire has been studied for the purpose of fire resistance design.On the basis of proper material properties and boundary condition,the study established a simulation model for square steel tube confined reinforced concrete column under three-side fire by the finite element software ABAQUS.The model has been testified by existed experimental results,subsequently,the effects of load ratio,slenderness ratio,section size,load eccentricity and steel ratio on fire resistance have been analyzed.The results showed that the load ratio as well as slenderness ratio are the main factors.The fire resistance decreases with the increase of load ratio and slenderness ratio.The simulation results are showed as below in detail:the load ratio increases from 0.4 to 0.6,the fire resistance decreases by 54.60%;the slenderness ratio increases from 20 to 40,the fire resistance decreases by 25.68%.On the contrary,with the steel ratio increase from 2%to 4%,the fire resistance also increases with the amplitude of 10.94%.While the effects of load eccentricity are quite complex that the ultimate bearing capacity rapidly improved with w/i=-0.2.In conclusion,using small slenderness ratio and high steel ratio can promote the fire resistance of square steel tube confined reinforced concrete column under uniform fire.
作者
叶友林
孙雅珍
张玉琢
YE Youlin;SUN Yazhen;ZHANG Yuzhuo(School of Civil Engineering,Shenyang Jianzhu University,Shenyang,China,110168)
出处
《沈阳建筑大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第4期603-611,共9页
Journal of Shenyang Jianzhu University：Natural Science
基金
国家自然科学基金项目(51808352)
辽宁省自然科学基金项目(2018011666-301)
沈阳市建委科技计划项目(SYJW2019002)。
关键词
三面受火
方钢管约束钢筋混凝土
有限元模拟
耐火极限
three-sided fire
square tubed reinforced concrete
finite element simulation
fire resistance
