Finite Elemtnt Analysis Of Cable-Stayed Bridge Under Static And Wind Loadings

Cable-stayed bridge is a kind of widely used bridge in medium and long span bridges. With the territory redistribution of energy, more and more cable-stayed bridges are used for energy transportation. In this thesis, finite element analysis is performed to study the cable-stayed bridge under static and dynamic loadof wind. Main contents and conclusions are as follows:First, by analyzing structure of the bridge and mechanical simplication, the basic geometric medel was defined, and a 3D model of a cable-stayed bridge which is composed of main cables, wind cables, towers, main beams and oil pipes wsa established by using the internationally famous software ANSYS. APDL language is applied so that the model can be parameterized.Second, based on the method of the finished state of a bridge, trial and error calculations are performed to complete the finished state of the cable-stayed bridge. Then the maximum stress and displacement of different parts in this state are analyzed. Base on the state, the stress and displacement of the bridge under maximum static load case are obtained. To estimate by the correlative codes of engineering design, the stress and displacement are within the safe range. So it is satisfactory for engineering design. Third, wind load types and resistance methods for cable-stayed bridges are analysised and generalized. By using the model of the bridge, response of the bridge under the action of Karman Vortex is analyzed, and the rules of freguency changes with the change of amplitude of vibration in the center ans cables of the bridge are obtained.Finally, after considering all kinds of wind resistant methods, the oil damper is chosen for this bridge. Spring elements with proper damping ratio, are used to simulate the damper, and the amplitude of vibration response curves with the changes of freguence for the center and each cables of the bridge. The results are compared with the curves without dampers.It is found that the maximum amplitude of vibration is only 1/3 of the ones without dampers. So, installing oil dampers for this bridge is a feasible wind resistance method.