以湘潭四大桥桁架拱为工程背景，进行了三种规格的K型钢管混凝土节点的疲劳试验，基于热点应力计算了K型钢管混凝土节点的疲劳荷载幅值，表明热点应力法能够较好地评估钢管混凝土节点的疲劳寿命；试验表明K型钢管混凝土节点的疲劳性能明显优于K型钢管节点。在此基础上初步提出了K型钢管混凝土节点的S—N曲线，对建立K型钢管混凝土节点疲劳寿命设计准则具有一定的参考意义。

Based on the truss arch of Xiangtan 4th Bridge, we made fatigue property test on concrete filled steel pipe K-joints of three different specifications, and calculated the amplitude of fatigue load of concrete filled steel pipe K-joints with hot-spot stress approach in this paper, which presented that hot-spot stress approach can be used to assess fatigue life of concrete filled steel pipe, and fatigue property of concrete filled steel pipe K-joints was obviously better than that of steel pipe K-joints. Moreover, the S—N curve of concrete filled steel pipe K-joints proposed by this paper would be of referential significance for building design criterion of fatigue life of concrete filled steel pipe K-joints.