Vibration Comfort Analysis And TMD Control Of Long-span Pedestrian Bridge Under Wind Crowd Load Coupling

In recent years,due to the requirements of building functions and the development of structural technology,large-span flexible structures are more and more used in large-scale public buildings.The slender and beautiful shape,light and high-strength steel and the function of space conversion make this kind of structure usually have the structural characteristics of large span,light weight and small rigidity,which makes it easy to produce large structural vibration under the action of dynamic load,and affects the normal use and even the safety life of the structure.In this paper,taking the long-span ribbon pedestrian bridge of Suzhou cultural and Expo Center as the research object,the dynamic response and vibration control of the structure under crowd load and wind load,dynamic response analysis under wind crowd load,structural vibration reduction control and optimization design under wind crowd load and other key issues are systematically carried out The research of response analysis and optimization method of vibration reduction mainly includes:1.Firstly,the three-way single foot walking curve and the single person walking load model are summarized,and combined with the relationship between crowd density and walking frequency,the crowd load is simulated.Then,based on the wind tunnel test data of Suzhou culture and Expo Center,a three-dimensional wind field simulation is carried out.Finally,the analysis of human induced vibration response,wind-induced vibration response and dynamic response of wind crowd load are carried out respectively,and the relationship between acceleration response,crowd density and wind speed is fitted.2.Based on the classical den Hartog optimization design formula,the MTMD vibration reduction system of long-span floating belt type pedestrian overpass under the action of pedestrian load,wind load and wind crowd load is designed respectively,and the vibration reduction effect under different loads is compared and analyzed.3.The MTMD control system of the long-span floating pedestrian bridge is optimized by using genetic algorithm.Through the parametric analysis of TMD,the acceleration response value and the mathematical relationship between the TMD travel and the damping ratio and frequency ratio of the MTMD damping system are fitted.The optimized design of the MTMD is realized by using MATLAB programming.