高温蠕变对约束高强度Q460钢梁抗火性能的影响  

Effect of High Temperature Creep on the Fire Resistance of Restrained High Strength Q460 Steel Beams

作　　者：何平召 王卫永[2,3] HE Pingzhao WANG Weiyong(Chengdu JZFZ Architectural Design Co. , Ltd. , Chengdu 610031, China School of Civil Engineering, Chongqing University, Chongqing 400045, China Key Laboratory of New Technology for Construction of Cities in Mountain Area（Ministry of Education）, Chongqing University, Chongqing 400045, China)

机构地区：[1]成都基准方中建筑设计有限公司,成都610031 [2]重庆大学土木工程学院,重庆400045 [3]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《建筑钢结构进展》2016年第5期34-40,共7页Progress in Steel Building Structures

基　　金：重庆市自然科学基金(cstc2013jcyjA1041);首批重庆市高等学校青年骨干教师资助计划

摘　　要：高温和荷载共同作用下钢材产生明显的蠕变变形,对钢结构在火灾下的变形和受力性能产生较大影响。为了研究钢材高温蠕变对约束高强度Q460钢梁抗火性能的影响,采用ANSYS有限元软件建立约束钢梁结构分析模型,引入普通钢材高温力学性能和蠕变特性,分析了约束普通Q345钢梁的火灾响应,并与试验结果进行了对比,验证了模型的正确性。采用验证后的模型,引入高强度Q460钢材的高温力学性能和蠕变模型,分析了高温蠕变对约束高强度Q460钢梁抗火性能影响的程度,并将约束普通Q345钢梁和高强度Q460钢梁的抗火性能进行了对比。最后对考虑蠕变效应后影响约束高强度Q460钢梁的抗火性能参数进行了分析。研究表明,钢材高温蠕变对约束高强度Q460钢梁的抗火性能影响很大,蠕变不利于约束Q460钢梁抗火承载力的发挥;约束高强度Q460钢梁比普通Q345钢梁的抗火性能好,约束钢梁的极限状态可以按钢梁达到轴向最大拉力时进行设计。Significant creep deformation occurs in steel subjected to high temperature and loading.This has an important impact on the deformation and load bearing capacity of steel beams in fire.In order to assess the influence of creep at elevated temperatures on load bearing capacity of restrained high strength Q460 steel beams,finite element analysis is conducted using ANSYS,with account of high temperature mechanical properties and creep.Fire resistance of restrained Q345 steel beams is simulated,and the comparison is made between test data and analytical results.The results indicate the model is well correlated.The influence of creep on the fire resistance of restrained high strength Q460 steel beams is studied by applying the validated model with high temperature material and creep properties.The fire resistance of restrained Q460 steel beams is compared with that of Q345 steel beams.Finally,parametric study is conducted on the parameters affecting the fire resistance of restrained high strength Q460 restrained steel beams.The study shows that the creep has a significant influence on fire response of high strength Q460 steel beams,and it canreduce the development of axial force in steel beam.The fire resistance of Q460 steel beam is better than that of Q345 steel beam.The limit state of restrained steel beam can be designed as the moment when the maximum tensile force develops in restrained steel beams.

关 键 词：蠕变 约束钢梁 高强度Q460钢 抗火性能 有限元分析 

分 类 号：TU352.5[建筑科学—结构工程]