Fatigue Analysis On Upper Steel Structure Of Wuhan Railway Station Caused By Train Load

As the rapid developments of railway construction in our country and higher speed of trains, the structures of large-scaled railway stations nowadays has been developing towards the directions of huge size, multifunction and spatialization. More and more large-span spatial steel roof structures with unique shapes and novel forms appear. The large-span spatial steel roof structures own specialities such as good rigidity, light weight, fine flexibility and small amortization. However, because of the main use of steel structure and susceptivity of steel structure especially the one that the welding steel structure to dynamic load, endurance failure of this structure will be aroused by the endurance of a long-period dynamic load. Wuhan station of the special line for passenger transport between Wuhan and Guangzhou has adopted a new structure mode of a joint of station and bridge. The base of the upper large span roof featuring space lattices is the pier of the railway bridge. As a result, the vibrations causing by high-speed trains transmit to the upper large span roof directly, and it will endure dynamic actions of trains for a long time. It makes us to worry about its safety. Therefore, study of characteristics of endurance that the large span roof featuring space lattices bears under trains'vibrating load and calculation and evaluation of its endurance life have an important significance to ensure the safe use of Wuhan station.In this study, dynamic response of upper structures of station subjected to train loading is calculated, then the fatigue performance of structures is analyzed. The main conclusions of this study could be summarized as follows:1. Dynamic response characteristic of bridge subjected to train loading is analyzed by traveling load-bridge basic theory, obtaining support reaction of bridge.2. Use the support reaction as input load of upper large span steel structures, dynamic response of upper large span steel structures is calculated. The information of the maximum stress of each structure components are presented and structure weak parts are determined.3. Fatigue characteristic of the structure weak parts (the maximum stress parts) is evaluated based on Miner theory.4. Establish the fine finite element modes of V pattern bracing upper cast steel nodes and patten cast steel nodes, the modes contain weld joints. Internal force of weld joints is calculated through applied internal force to modes. Fatigue characteristic of the two kinds of nodes is evaluated based on hot spot stress method and Miner theory.5. Conclusion shows that the vibrations causing by high-speed trains have no influence on fatigue life of structure weak parts and two important nodes. The upper steel structures of Wuhan railway station can satisfy the requirement of fatigue life in the design term.6. At last, based on the summary of the whole content, and provided the problems which need further study.