Analysis Of The Parametric Vibration And Mitigating Of The Cable In Cable-Stayed Bridges

The stay cable is one of the principal force members of cable-stayed bridges, and almost supports the all dead load and live load. It would be vulnerable to a variety of harmful vibrations due to its inherent properties of high flexibility, little weight and low damping. The theoretic analysis and test research of the parametric vibration for the stay cable are conducted in this paper. The main works and results are as followings.The theoretical model of parametric vibration of cable on the cable-stayed bridges is established and the reason of parametric vibration is explained. The Finite Element Model of the single cableis also founded, and the effect of factors such as inclination angle, damp and original tension for the vibration amplitude are studied.The cable parametric vibration experiment is conduced with a prototype cable. The relationship of parametric vibration amplitude versus ratio (ratio of excitation frequency to modal frequency) and excitation amplitude, the frequency ratio range of parameter vibration occur, are obtained.Experiment of mitigating parameretic vibration by adding the damper for the prototype cable is carried out. The effective measure for preventing parametric vibration is put forward.Taking Edong Bridge as background, the modal frequency and mode of the bridge and stay cable are obtained by FEM analysis. With comparative analysis of modal frequency of cable and bridge, the possible cables of parametric vibration in Edong Bridge are ascertained. Mitigating measures are also put forward.