The Finite Element Analysis of the Large Span Steel Truss Arch Bridge´s Node Fatigue Test

Chongqing Chaotianmen Yangtze River Bridge with the main span of 552m is an urban bridge of double deck bridges for highway and rail, which need to verify fatigue security performance of the node on bottom chord . Through the calculation of the full bridge´s space finite element, the node for study is determined as the M29 and calculate and calculate the internal force influence line of M29. Load according to standard fatigue vehicle of AASHTO, BS5400 and metro standard and obtain the internal force history of M29. Based on rain-flow counting method and Miner´s law of fatigue damage, identify the load of 2 million cycles of fatigue test in this model of joint test. According to the result of finite element calculation,complete the conversion from the nodes of actual bridge to the large-scale model of 1/2 and the node´s fatigue test. Through the comparison of the experimental results and theoretical calculation, the authenticity and reliability of test data and the safety of the joint connection during the 2 million´s fatigue life period are verified. Finally, the calculation results of the node model´ fatigue life shows that the lower part of the connection between the transverse beam´s web and angle steel, which is verified by fatigue tests. The research results provide reference for the fatigue test and structure design of this kind of bridge in the future.