The Vibration Of Cable In Cable-stayed Bridge And The Vibration Recduction

In recent years, the cable-stayed bridge has made enormous progress in the world ,because of its reasonable structure form,superior span,pleasing shape,good mechanical properties and relative budget cost. Nowadays, it becomes one of the fastest developing and the most competitive bridge in the modern bridge engineering. At the same time , as the growing longer span of the cable-stayed bridge, its frequency will be lower and the bridge will be sensitive to have external-induced vibration, which induces stay cables to vibrate more easily. It is necessary to have a study on the vibration of stay cables and the vibration recduction.In this paper, different classic wind induced stay cable vibration and the common method of cable vibration recduction are firstly introduced, of course includes new forms of vibration which were found in recent years: the high-speed vortex excitation and the galloping instability of inclined cable. When the wind blow across the bridge, it may cause the buffeting of the bridge .The second part of this paper is concerned with the parametric vibrations of the cable which caused by the buffeting of the cable-stayed bridge, building the cable-stayed bridge model in ANSYS and simulate the cable using an appropriate element, programming and apply each cable with time-varying displacement at the support which lies to the bridge, obtain the swing of each cable, then apply the oil-damper to some of the cable which have a biggish swing, and the results of the vibration recduction are satisfactory.At last, this paper have a research on the oil-damper,including the infection of the damper value and the height, angle of the oil-damper that are placed on the cable to the vibration recduction, what is more, drawing graphs of the vibration recduction of the oil-damper. From the graphs, it can be seen that the height which the oil-damper is placed on the cable is determined, then the maximal mitigation effect of cable vibration is also determined, but when the axes of the oil-damper is perpendicular to the axes of the cable, the damper value is minimal and the conclusion will be helpful to the use of oil-damper.