Vibration-reduction Design Method For The Wind-induced Buffeting And The Vehicle-bridge Coupling Vibration Of Cable-stayed Bridge Using MTMD

For the long span cable-stayed bridges, wind and vehicle are the two main factorsthat induce vibrations, resulting in fatigue and loss of trafficability of bridges.Therefore vibration control of the bridges is necessary. At present, TMD/MTMD isone of the main technologies for bridge vibration control. But due to the complexityof the analysis to wind-induced vibration and vehicle-bridge coupling vibration,together with the difficulty of the MTMD parameter optimization, thevibration-reduction design using MTMD is not well understood for engineers. In thispaper, a study on wind-induced vibration and the vehicle-bridge coupling vibration ofQingzhou Bridge of the Hongkong-Zhuhai-Macao Link and the vibration-reductiondesign of the bridge using MTMD are carried out. Through a large amount ofnumerical simulation and analysis, design procedure and associated parameters forbridge vibration control design is proposed. The main contents of dissertation are asfollows:(1) Vibration control theory of TMD/MTMD and design parameter optimizationare summarized and reviewed. Robustness and control efficiency of TMD/MTMD arecompared and MTMD is preferable in terms of the these two index. Among the5kinds MTMD modes with different frequency ranges, the Model-1has the best controlperformance and applicability.(2) A finite element model of Qingzhou Bridge using ANSYS is established.Buffeting analysis of the bridge in frequency domain is conducted, and optimalparameters of MTMD system are proposed. Time domain analysis of buffeting of thisbridge is also carried out, and the effectiveness of MTMD system for suppressingwind-induced vibration of the bridge is verified.(3) The vehicle-bridge coupling vibration analysis method is studied. Based onthe traditional separation iteration method, a new separated iterative method with modalanalysis is proposed. The optimal parameters of MTMD system for reducing thevehicle-bridge coupling vibration are given. A program for vehicle-bridge couplingvibration analysis is developed, and the efficiency of MTMD for vehicle-bridgecoupling vibration reduction is validated.(4) Taking Qingzhou Bridge and Jiuzhou Bridge as examples, through a largeamount of numerical simulations and analysis, the factors that influence the optimalparameters of MTMD system for wind-induced buffeting and vehicle-bridge couplingvibration are analyzed. A unified form of the optimal parameters of MTMD forengineering application is given. A notion of "relative efficiency" to measure the vibration control efficiency of bridges under wind load and vehicle load is presented,and the optimal parameters of MTMD under reference conditions are given.