| The construction technology level of long-span spatial structure is an important symbol to measure the construction technology level of a country or region.Large-span spatial structure has the characteristics of beautiful shape,fast construction speed,large usage area and good economic benefit.It has been used more and more in practical engineering.However,large-span spatial structure also has some shortcomings,such as small damping,light weight and large flexibility.It is a typical wind-sensitive structure.It is easy to be affected by external wind load in the use process,and it is easy to cause dithering of long-span spatial structure,even cause structural damage,bring people psychological panic.In order to maintain enough stability and safety of large-span spatial structures,it is necessary to control the vibration of structures.Tuned mass damper(TMD)is one of the passive vibration reduction technologies,which has the advantages of simple structure,easy installation and low cost.TMD plays an important role in the field of structural vibration reduction.At present,TMD have been widely studied in floor,pedestrian bridges and high-rise structures,and the research on vibration reduction of TMD in long-span spatial structures is still lacking.In order to make TMD work efficiently,stably and reliably in vibration control,it is also an urgent problem to be solved in practical engineering applications.Based on the project of Bengbu Sports Center Stadium,the wind field environment around the large cantilever steel structure roof of the stadium is studied,and the vibration reduction effect of multiple tuned mass dampers(MTMD)in the large cantilever steel structure roof of the stadium is discussed.The research work mainly includes the following parts:(1)The field dynamic response test results of large cantilever steel roof of Bengbu Sports Center Stadium are introduced in detail.The wind-induced vibration response of large and small steel roof with or without tuned mass dampers is analyzed in depth.The vibration reduction effect of MTMD is analyzed in detail by introducing vibration reduction coefficient,and its vibration reduction effect is verified by actual measurement.(2)The wind tunnel test results of the large cantilever steel structure roof of Bengbu sports center stadium is described,analysed the distribution of wind pressure coefficient on the roof surface under wind tunnel test,and understood the unfavorable position of the structure under different wind loads;establishes the finite element model of the stadium,simulates the wind field around the stadium by using Fluent software,and gives the numerical simulation.Methods,turbulence model,treatment method of turbulence near wall boundary layer,etc.Comparing finite element calculation results with wind tunnel test results,the correctness of numerical calculation model is verified,and the wind field around large cantilever steel structure roof is analyzed intuitively from the flow field distribution.(3)The program of wind gradient in the atmospheric boundary layer is compiled by using MATLAB software.The time history curves of wind speed and pressure around the roof are simulated by AR method,and the time history curves of wind speed at different heights are calculated,which lays a foundation for subsequent structural vibration analysis.(4)The finite element software ANSYS is used to establish the large cantilever steel structure roof model of Bengbu Sports Center Stadium and analyzed its dynamic characteristics.The wind speed and pressure time history curves calculated by simulation are applied to the roof to analyze its wind-induced response,and the displacement response,velocity response and acceleration of the large and small roof steel structure under different wind loads are analyzed respectively.(5)The working principle and Simulation of tuned mass dampers are described.The dynamic response of steel roofs with large and small sheds under different wind loads is studied.The dynamic response of roofs with and without MTMD is compared and analyzed.The vibration reduction rate of MTMD is calculated to validate its vibration reduction effect effectively. |
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