Research On Fatigue Performance Of The Open Truss Combined Girder Bridge Made From Steel Pipe Concrete

This paper firstly outlines the basic concept of truss bridge and the advantages ofsteel pipe concrete. On this basis, this paper put forward the truss combined girderbridge made from steel pipe concrete, and forecast the development trends. Brieflyintroduces the classification and development of domestic and international researchsituation of shear connectors. And introduce the present status of composite structurejoint fatigue and the basic theory of fatigue.Secondly, the paper takes the60m through cross-dike approaching bridge on theexpressway Xuzhou-Mingguang as an engineering background. Based on theconstruction drawings and construction plants of the engineering, a finite elementmodel of entire bridge is established with beam element using MIDAS/CIVIL, whichis a large-scale finite element software. Analyze static characteristic at the bridgeoperation stage. And analyze the upper structure’s behavior under different loadconditions in detail. According to the analysis results, find the open truss combinedgirder-bridge’s dangerous point.Third, the paper combines the model calculation results with field monitoring data.Choose the truss bridge’s dangerous node to do full-size fatigue test. Study thedangerous node’s static test and fatigue test for2million times. After2million fatigueloading，there is no damage of the model，meet the design requirements.Finally, use MIDAS/FEA build the open truss combined girder bridge’s dangerouspoint of the fatigue test. By compare the model’s analysis data with experimental data,make sure the accuracy of the finite element model. Then, increase load, find the testpoint’s ultimate bearing capacity much larger than its design value under2millionfatigue load.