摘要
采用蠕变试验机对低合金Q345钢进行高温蠕变试验,得到高温下的蠕变曲线。基于试验数据和现有蠕变模型,拟合得到Q345钢复合时间强化蠕变模型和Norton蠕变模型。利用蠕变模型对Q345钢柱的抗火性能进行分析,得到高温下Q345轴压钢柱承载力与受火时间关系曲线以及ISO 834标准升温条件下钢柱的荷载比和临界温度的关系。研究表明：Q345钢在700～800℃断裂前蠕变变形达到最大值;考虑蠕变后钢柱受火初期的承载力随受火时间的延长急剧降低,随后趋于稳定;ISO 834标准升温条件下,荷载比在0.2～0.8内考虑蠕变后钢柱的失效临界温度降低60℃左右。
Creep test at elevated temperature was carried out on Q345 steel using creep test setup. Creep strain curves for steel at elevated temperatures were obtained. According to the test data and current creep models, creep models for Q345 steel, including combined time-hardening creep model and Norton creep model, were proposed. The fire resistance of Q345 steel column was analyzed by employing proposed creep models and the relationship between load bearing capacity and time duration in fire, load ratio and critical failure temperature under ISO 834 standard fire curve, were predicted. The study shows that creep deformation reaches a maximum magnitude before rupture during 700-800 ℃. The load bearing capacity decreases significantly with the increase of time duration in fire, and then keeps almost constant. Critical failure temperature of steel column decreases approximately 60 ℃ for the load ratio range of 0.2-0.8 and under the fire exposure to ISO 834 standard temperature curve.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第11期47-54,共8页
Journal of Building Structures
基金
国家自然科学基金项目(51678090)
重庆市自然科学基金项目(CSTC2013JCYJA30010)
