| Wind disaster is a very serious natural disaster.The global losses caused by wind disasters amount to nearly 10 billion dollars every year.The research shows that flexible structures such as high-rise buildings,high-rise structures and long-span structures are sensitive to wind loads,and are prone to large-scale vibration and damage under strong wind.In extreme cases,some high-rise structures collapse from time to time.At present,the commonly used structural wind resistance analysis methods mainly include theoretical analysis,wind tunnel test and numerical wind tunnel.However,the characteristics of relatively low accuracy of theoretical analysis methods and high cost of wind tunnel test make the research of numerical wind tunnel more and more concerned.At present,the numerical analysis of wind-induced vibration control of tuned liquid damper(TLD)structures often equates the TLD and the wind field into the form of external load.The two equivalent processes greatly affect the accuracy of numerical analysis.Therefore,this paper carries out wind field Study on air-solid-fluid coupling simulation method between high-rise structure and tuned liquid damper.Firstly,the shaking table test and liquid sloshing simulation of pure water ATLD are carried out,and the parameter analysis is carried out to verify the correctness of the numerical simulation of ATLD proposed in this paper.Then the numerical simulation of different sizes of ATLD is carried out,and the damping ratio formula of pure water ATLD proposed in this paper is improved on the basis of the previous pure water circular TLD damping ratio formula;Because the damping of pure water ATLD is small,the anti sway plate is installed in pure water ATLD,and the test and numerical simulation are carried out.The results show that the numerical simulation of liquid sway based on CFD after installing the damping device is correct.After adding the anti sway plate,the damping ratio of ATLD increases by 29.48% on average and 77.28% at most,from 0.017 to 0.031;Based on the anti sway plate,a more effective damping device square hole grid is designed and numerical simulation is carried out.The results show that the damping ratio of ATLD is increased by321.15% on average and 501.71% on the maximum compared with pure water,from 0.0234 to 0.1408,and the average damping ratio of the increased part is 10.89 times that of the increased part of the anti sway plate.At the same time,a damping ratio formula for setting the square hole grid is proposed;The damping ratio formula of ATLD is obtained by combining the pure water damping ratio formula and the square hole grid damping ratio formula.Then,the wind load characteristics of a steel chimney test model are studied,the wind pressure distribution and shape coefficient are obtained,and compared with the shape coefficient given in the load code for building structures.The results show that the shape coefficient is close to the code value,which proves the correctness of the wind field.The airsolid coupling simulation of the steel chimney model is carried out based on the fluent module,transient structural module and couple module in the ANSYS Workbench.The maximum values of displacement,velocity and acceleration at the top of the model under unidirectional coupling are 0.085 m,0.417m/s and 3.0698m/s2,and the maximum values of displacement,velocity and acceleration at the top of the model under bidirectional coupling are 0.039 m,0.168m/s and 0.578m/s2,Because the structure will produce aerodynamic damping due to the change of wind field in the two-way air-solid coupling,the wind-induced vibration response of the structure under the one-way coupling is greater than that under the two-way coupling.Then the random subspace method identifies that the aerodynamic damping ratio of the steel chimney is 0.67%.Finally,several different methods for studying the vibration reduction of TLD structure system are introduced,and the method of air-solid-fluid coupling is proposed;The ATLD is designed according to the steel chimney.The mass ratio is 0.85% and the frequency ratio is0.92.The square hole grid with opening rate of 72.02%,grid thickness of 1cm and square hole size of 1cm is selected as the device to increase the damping ratio of ATLD.The damping ratio is 0.024.In order to simplify the calculation,the effect of square hole grid is equivalent to the dynamic viscosity of liquid through the ATLD formula fitted in this paper.The dynamic viscosity is calculated to be 1.5.The ANSYS Workbench is used to carry out air-solid-flow coupling on the steel chimney equipped with ATLD.When the air-solid unidirectional coupling and the fluid-solid bidirectional coupling,the average vibration reduction rate of ATLD on the structure is 58.01%,and when the air-solid-fluid are both bidirectional coupling,the average vibration reduction rate is 45.43%,and the root mean square of displacement,velocity and acceleration in one direction are 1.68 times,1.85 times and 1.95 times of that in two directions. |
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