国产高强度Q960钢高温蠕变及其对钢柱抗火性能影响  

Creep of domestic high strength Q960 steel at elevated temperature and its effect on fire resistance of steel columns

作　　者：李翔 王卫永[1,2] 张艳红 Li Xiang;Wang Weiyong;Zhang Yanhong(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]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：《土木工程学报》2021年第6期26-34,共9页China Civil Engineering Journal

基　　金：中央高校基金基本科研业务费项目(2019CDQYTM027);国家自然科学基金(51878096)。

摘　　要：为获得国产高强度Q960钢高温下蠕变应变,对Q960钢进行高温拉伸蠕变试验,得到不同温度和应力水平下的蠕变应变-时间曲线,基于试验数据,提出适用于Q960钢结构抗火分析的蠕变模型。采用有限元模型分析蠕变效应对Q960钢柱抗火性能的影响,得到标准升温条件下无防火保护Q960钢柱的临界温度,并与《建筑钢结构防火技术规范》(GB 51249)计算的结果进行对比。研究表明:当温度超过600℃时,Q960钢材具有明显的蠕变效应,且温度越高,断裂前蠕变总变形越大;蠕变效应会显著降低Q960钢柱的临界温度和耐火极限;《建筑钢结构防火技术规范》(GB 51249)中的临界温度法不适用于Q960钢柱,当荷载比小于0.75时,计算结果不安全,而荷载比大于0.75时,计算结果偏于保守。In order to obtain the creep strain of domestic high strength Q960 steel at elevated temperature,tensile creep tests at elevated temperatures were carried out to generate the creep-time curves under various temperature and stress levels.A creep model of Q960 steel suitable for analysis fire resistance of Q960 steel structure was proposed based on the test data.A finite element model was established to analyze the creep effect on the fire resistance of the Q960 steel column.The critical temperature of bare Q960 steel columns was obtained and compared with that code for fire safety of steel structures in buildings(GB 51249).The research results show that the Q960 steel has a noticeable creep strain when the temperature exceeds 600℃,and the higher the temperature is,the greater the total creep deformation is before fracture.The creep effect can significantly reduce the critical temperature and fire resistance of Q960 steel columns,and the critical temperature method in GB 51249 is not suitable for the Q960 steel columns.When the load ratio is less than 0.75,the calculation result of GB 51249 is unsafe.While when the load ratio is more than 0.75,the calculation result is conservative.

关 键 词：国产高强Q960钢 高温蠕变 蠕变模型 有限元分析 

分 类 号：TU391[建筑科学—结构工程]