摘要
由于钢管混凝土叠合柱(ST-RC)具有良好的抗震性能和耐火性能,本文对矩形截面钢管混凝土叠合柱在标准火灾全过程(包括升温、降温阶段)下的热学性能进行了数值研究。利用Abaqus有限元分析软件建立矩形截面钢管混凝土叠合柱的热学分析模型,结合相关试验数据对模型的准确性进行验证,并对标准火灾升温、降温全过程下试件的温度场分布情况进行分析。结果表明:矩形截面钢管混凝土叠合柱在标准火灾升温下的温度场分布呈现双轴对称形态,外围混凝土厚度较大的长轴方向上构件内部测点的温度相对短轴方向更低;在火灾作用的全过程中,混凝土的温度变化存在滞后现象,使得试件受火表面之间距离越大的区域升温、降温的滞后时间也越长;在降温的最终时刻,截面温度场分布为内高外低形式,与升温结束时刻的温度场分布方式相反;与升温结束时刻相比,火灾后(历史最高温度)的温度场中混凝土材料达到劣化温度的区域面积更大,采用历史最高温状态的温度场进行火灾全过程中叠合柱结构相关力学性能的计算时更安全。
A numerical study of thermal performance of Steel Tube-Reinforced Concrete(ST-RC)columns with rectangular cross section in the whole process of standard fire(including heating and cooling phases)is conducted in this paper since ST-RC has good seismic performance and fire resistance.The thermal analysis model of ST-RC columns with rectangular section is established by using finite element analysis software ABAQUS.The accuracy of the model is verified combined with experimental data.The temperature field distribution of the sample is analyzed in the heating and cooling process of standard fire.The results show that the temperature field distribution of ST-RC columns presents a biaxial symmetry under the heating action of standard fire.The temperature of internal measuring point of the component in the long axis with large peripheral concrete thickness is lower than that in the short axis.There is a lag in the temperature change of concrete in the whole process of fire,which makes the lag time of heating and cooling longer in the area with greater distance between fire surfaces;the distribution of cross section temperature field is high inside and low outside at the final moment of cooling phase,which is opposite to that at the end of heating phase.The area where the concrete reaches the deterioration tempe-rature in the temperature field after the fire(the highest temperature in history)is larger compared with that at the end of heating phase.It is safer to calculate the mechanical properties of laminated column structure in the whole process of fire by using the temperature field of the highest temperature in history.
作者
陈博文
王高雄
包延红
CHEN Bowen;WANG Gaoxiong;BAO Yanhong(School of Civil Engineering,Qinghai University,Key Laboratory of Energy-saving Building Materials and Engineering Safety of Qinghai,Xining 810016,China)
出处
《青海大学学报》
2022年第2期71-77,共7页
Journal of Qinghai University
基金
青海省科学技术厅项目(2019-ZJ-971Q)。
关键词
钢管混凝土叠合柱
矩形截面
火灾全过程
数值模拟
温度场
Steel Tube-Reinforced Concrete(ST-RC)columns
rectangular cross section
whole process of fire
numerical simulation
temperature field
