(上海交通大学土木工程系，上海 200240)

［摘要］介绍了利用ABAQUS软件计算平面桁架结构在火灾作用下的极限承载力和耐火极限的方法，并对平面桁架结构进行了火灾作用下的抗火性能分析，得出了在不同火灾温度下的极限承载力和不同荷载比下的耐火极限温度，并对计算结果进行了分析比较。结果表明，20～200℃时，桁架的承载力变化不大，温度在400℃以上，承载能力急剧下降；随着荷载比的增大，结构的耐火极限温度线性降低。

［关键词］平面桁架；抗火性能；极限承载力；耐火极限；有限元

Study on mechanical performance of steel planar truss under fire

Liu Minglu, Zhao Jincheng, Jin Meng(Department of Civil Engineering，Shanghai Jiaotong University，Shanghai 200240，China)

Abstract:Method for calculating the load bearing capacity and fire-resistance temperature for planar truss under fire by using the finite element software ABAQUS was introduced. Analysis of mechanical performance for planar truss under fire was also conducted. The limit load bearing capacities under different temperatures were obtained, as well as the fire-resistance temperatures under different load ratios. Comparisons of analytical results were made. The results indicate that when the temperature is at 20～200