Buffeting Response And Fatigue Damage Analysis Of Cables In Steel Truss Stayed-cable Bridge

Buffeting is a randomly vibration phenomena caused by fluctuating wind, that is,the fluctuation of turbulent flow caused forced vibration on Structure. Although the buffeting response caused by turbulent flow does not create destructive damage, it may cause local fatigue damage, discomfort and high-speed traffic safety and so on, therefore, the analysis of buffeting for long-span bridges is one of the important tasks in wind resistant design.As the key component of cable-stayed bridge,the buffeting response and fatigue damage analysis of stay cable is limited,therefore, the analysis of stay cable buffeting response and fatigue damage is particularly important.In this paper,with the subsidize of National Natural Science Youth Foundation Project "Study on the damage evolution of sensitive members for bridges based on the multi-scale analysis theory (NO.50808175)", taking Yujiang two line steel truss girder cable-stayed bridge on the Nanning-Guangzhou Railway as project background, the analysis of buffeting response and fatigue damage of stay cable is carried on,the main research is as follows:1. Matlab has been applied to program composition by WAWS method,Which simulated three-dimensional fluctuating wind field on the beam,main tower and within the range of the stay cable.2. The finite element model of Yujiang steel truss girder cable-stayed bridge is established to analyze the dynamic characteristics.Time-domain analysis of wind-induced buffeting is completed by using transient analysis of ANSYS,which obtained the buffeting response time history at different wind speed and different wind yaw angle.3. Based on rain-flow counting method, composition is programed by Matlab to count stress amplitude of stayed cable.The fatigue damage analysis model of stayed cable is established by the proposed S-N curve of the wire and miner criterion,which can analyze the fatigue damage of the stay cable accordingly.