Fatigue Properties Analysis Of The Overall Node Of Through Truss Steel Bridge

With the increase of large span railway steel bridge and welding technology matured, overall node technology has been widely used in the railway steel bridge, but fatigue issues have become increasingly prominent. As the speed of the train has a great effect on the bearing capacity of the bridge, it is significant for the safe use of the bridge to master bridge response under fatigue loading conditions and the fatigue properties of dangerous component.This article uses a through truss steel bridge as the engineering background to carry out the research work, combining with the advanced theories and methods at home and abroad, mainly from the dynamic response of the bridge under fatigue loading and fatigue performance of the overall node.Firstly, this article introduced the basic concepts of fatigue and the basic theory of fatigue, including of the characteristics and process of the fatigue damage, the S-N curve, load spectrum, stress spectrum, Internal forces of history, linear Miner cumulative damage theory and reviewed the advantages and disadvantages of the commonly used methods of fatigue life analysis.Secondly, the structural details of the overall node, factors affecting the fatigue strength, method of improving the fatigue performance of welded steel and fatigue properties of the overall node are reviewed in detail, and based on this, we should pay attention to the problems in the process of design and manufacturing.Again. combined with the specific design of a truss steel bridge, the detailed finite element model of the bridge is established. By comparing simulation results with the results of other studies to verify the reliability of the model. which can reflect the state of the real bridge, it can be used as a benchmark finite element model. On this basis, the fatigue loading applied to the bridge, it reveals the dynamic characteristics of the bridge in single, double, four-wire load, and select fatigue danger point depend on this.Finally, the fatigue analysis process and rain flow analysis process is introduced. The overall node static analysis and fatigue analysis is evaluated. The fatigue life of the whole node is evaluated under the nominal stress. Studies indicate that the bridge in a safe state in its’normal life, and fatigue failure did not occur.