摘   要：基于有限元分析建立了钢筋混凝土框架节点不同受火时间的温度场模型及火后的力学计算模型，采用热力耦合的方法，对节点进行低周反复加载，研究火后节点的抗震性能包括滞回曲线、骨架曲线的变化规律。结果表明，未受火和不同受火时间下，节点弹性阶段承载力几乎不变，而极限承载力在受火后将出现不同程度的降低，随着受火时间的增加，结构的承载力和刚度明显降低。

Abstract: The temperature field model of the reinforced concrete frame joints with different fire time and the mechanical calculation model after fire are established based on the finite element analysis. The joints are subjected to low cyclic loading. The post-fire seismic performance of the joints including the variation of the hysteresis curve and the skeleton curve are investigated by using the thermomechanical coupling method. The results show that the bearing capacity in the elastic phase is almost invariable under different fire time, and the ultimate bearing capacity will decrease in different degrees after the fire. The bearing capacity and stiffness of the structure are evidently reduced with the increase of fire time.