中文摘要：

基于有限元ABAQUS软件,通过建立温度场模型与静力加载模型,对外包薄壁钢管加固ISO 834标准火灾作用后的钢筋混凝土（RC）柱的轴压性能进行研究.分析外包钢管厚度、加固方式和截面形状对外包薄壁钢管加固火灾后RC柱的刚度、轴压承载力和极限变形能力等的影响规律.结果表明：外包薄壁钢管加固火灾后RC柱的刚度、轴压承载力和变形能恢复甚至超过火灾前试件的水平,且随钢管厚度的增加、加固方式的改变,以及加固后截面形状的不同,混凝土柱的受力性能有不同程度的提高.

英文摘要：

Based on numerical simulation（ABAQUS）,according to established the temperature model and the static load model,the axial compression performance of the reinforced concrete（RC）columns wrapped with thin-walled steel tube after exposure to ISO 834 standard fire was conducted.The thickness of steel tube,strengthening mode and cross section shape were analyzed to figure out the influence on axial bearing capacity,rigidity and ultimate deformation of the columns.Results show that the axial rigidity,axial bearing capacity and ultimate deformation of RC columns after fire wrapped with thin-walled steel tube may restore or even exceed the level of specimens before fire;as the thickness of steel tube increases,the strengthening mode and cross section change,the mechanical performance of RC columns enhances.