Tmd Parameter Study On Mitigation Of Vortex-Induced Vibration Of A Cable-Stayed Bridge With The Steel Box Grider

Being used around in worldwide, cable-stayed bridges are the most imaginable bridge type with the most configuration philosophy. This bridge type has become the mostly used one due to the advantage of small girder body, large span ability, and easy to construct because of slight restrain from bridge clearance and deck level. However, as a bridge type with flexibility, the cable-stayed bridges are easy to be influenced by wind effect. The possible consequences of wind are unstable vibrations, such as buffeting, vortex induced vibration, galloping, and flutter that the bridges suffer. These vibrations will either result in the bridge destruction, pedestrian’s feeling of uncomfortable, and vehicle unsafety. Taking a cable-stayed bridge named Jianghai navigation bridge as the example, the thesis studies one of the vortex-induced vibration control methods:adding tuned mess damper, and put forward the vibration control scheme.The main work of this thesis are as follows:First, a retrospect of basic theory and research methodology of vortex induced vibration is conducted and the control theory of TMD is presented by considering mess dynamic vibration reducing,damping dynamic vibration reducing and damping effects of main structure. Based on the theory, the wind tunnel tests of a large scale deck sectional model was conducted and the tests suggested that the bridge deck suffers vortex-induced vibration in vertical direction for two vibration modals, i,e. the first degree anti-symmetrical vertical bending and the first degree symmetrical vertical bending.The comfortableness of the bridge deck suffered vortex-induced vibration was evaluated combined with different standards.Second, research of influences of each TMD parameters on the efficiency of vibration control and the structure dynamic properties is conducted in combining with the finite element bridge-TMD calculation model and consequently the reasonable selection of TMD parameters is obtained.Lastly, Based on the TMD resonance theory, a TMD vortex-induced vibration control design is conducted for Jianghai navigation bridge and the results of vibration control under various mess ratios and damping ratios are studied in the paper.