Study On Vibration Control Of High-rise Structure Attached With Circular Tuned Liquid Damper

A tuned liquid damper(TLD)is a passive energy dissipation device that has been used successfully in suppressing the vibration of tall structures.It consist of one or multiple tanks,partically filled with water and rigidly attached to the structure.During a dynamic loading event,the vibration of the structure leads to the development of a sloshing motion for the liquid inside the tank.If the frequency of the sloshing motion is properly tuned to the nature frequency of dominant mode of the structure,the sloshing motion imparts an inertia force that acts against the structural vibration,this effect leads to a reduction in the structural response.In the practical engineering application of TLD,circular TLD is mostly used,However,there are few studies on circular TLD.In this paper,dynamic characteristics of circular tuned liquid damper(TLD)is studied.The main research works of this paper are listed below:(1)Firstly,the classical theories of shallow water TLD and deep water TLD are introduced.Through analysis,it is considered that for shallow water TLD,it is impossible to use its non-linear theory to explore the optimal design parameters.Therefore,the NSD model is chosen to optimize the parameters of shallow water TLD.the NSD model of shallow water TLD and the linear model of deep water TLD are optimized with H~2 based on genetic algorithm.According to the optimized results,the optimal tuning ratio and damping ratio curves of shallow water TLD and deep water TLD are fitted.It is considered that shallow water TLD can achieve the optimal damping ratio without additional damping devices,but deep water TLD needs some additional damping.The damping device is designed to achieve the optimal damping ratio.(2)By adding damping device in the water tank,the damping of liquid sloshing in deep water TLD is increased.Vibration characteristics of TLD with additional transverse baffles,vertical baffles and annular baffles were studied by shaking table test.The experimental results show that the vertical blade baffle can increase the liquid sloshing damping in TLD,but the effect is limited.When the cross blade baffle is used,the influence of the angle parameters between the excitation direction and blade baffle on the effect of the blade baffle can be eliminated.The increase of liquid sloshing damping in TLD by vertical plate is not obvious,but it can restrain the violent sloshing of liquid in TLD in resonance region,and make TLD achieve more stable vibration reduction effect.It is found that the annular baffles is the optimal additional damping device.When the width of the annular baffles is limited to 0.15times of the radius of the tank,the ratio of the depth of immersion to the depth of water purification is greater than 0.1,and the number of annular baffles is not more than two,the additional annular baffles will not have a significant impact on the linear characteristics of liquid sloshing in deep water TLD;The width and position of the annular baffles have some influence on the additional sloshing damping of the anti-sloshing plate,but the additional sloshing damping effect is not obvious when the number of annular baffles is increased,and the additional annular baffles will have a negative impact on the additional damping effect when the spacing between the anti-sloshing plates is too small;When the annular baffle is placed high,the formula derived by Maleki and Ziyaeifar can accurately calculate the damping of liquid sloshing in deep water TLD,but when the annular baffle is placed at a lower level,the calculated results of the formula are far less than the experimental values;The sloshing damping ratio of deep-water TLD can reach the optimal damping ratio when the annular baffle is added.(3)The optimization parameters are selected to calculate the wind vibration control of a 20-storey structure,and the AR model is used to simulate the wind fluctuating wind load in the wind field.On the basis of the calculation,the effect of TLD on the structure vibration control is analyzed.It is considered that the ratio of TLD's fundamental frequency to structural fundamental frequency is in the range of0.95-1.05,TLD has excellent effect of mitigating structure vibration.The best effect is to use the optimal parameter.Setting the TLD to the top floor works best.When TLD cannot be placed on the top floor of the structure due to structural constraints,setting TLD to other floors with large vibration amplitude can also achieve better vibration control effect.