The Study Of Wind-induced Vibration Of Three-dimensional Elastic Stay Cable

Cable-stayed bridge becomes the preferred long-span bridges bridge type because of the appearance and economy. Stay Cable is one of the main force component in cable-stayed bridge, and the cable has a smaller mass and damping, vibration occurs easily in the wind, rain and bridge vibration excitation generated as wake galloping, rain exciting, parametric resonance, vortex-induced resonance. Cable vibration will not only cause damage to the cable fatigue, but also pose a great threat to the safe operation of the bridge, has become one of the key issues need to be resolved long-span cable-stayed bridge. So Vibration Mechanism and Vibration Control of Cable is a topic of great engineering significance.This paper summarizes the theory of rain cable vibration, carries out three-dimensional elastic Cable wind tunnel tests, and proposed a calculation based on three-dimensional elastic segment model, and gives the equations of motion, static configuration, the rain line equation and aerodynamic equation of the cable.Using CFD technology to calculate the aerodynamic coefficients of bring-rain to the cable line, obtained aerodynamic coefficients of cable under different wind angles and different rain line initial position. Using high-order polynomial fitting function on aerodynamic coefficients and the initial position angle, get aerodynamic semi-empirical formula.Finite element analysis software ANSYS is adopted to establish the model, Carried out time history analysis in the rain for the cable-stayed excitation, Respectively to calculate the response of stay cable under the different wind speed, the rain line initial amplitudes, different rain line to the initial position and wind angle. Defines the optimal damping ratio, gets the optimum damping ratio through a feedback mechanism in the rain excitation.Through wind tunnel tests on the same conditions of different working conditions have been tested on the stay cable, compared the damping ratio under the same test results with the calculation results of difference, get relevant conclusions.