| Tuned mass damper as a kind of vibration energy dissipation device,has been widely used in structural vibration control because of its low installation and maintenance prices,stable and reliable performance and wide range of application.At present,many of high-rise buildings use TMD control wind-induced vibration.TMD is composed of mass,spring and damper.Its frequency ratio and damping ratio parameters will affect the control effect of TMD.Accordingly,based on the an existing project of high-rise structure,this paper carries out the following research work on the optimal design parameters of TMD:(1)Three-dimensional finite element model of the observation tower is simplified to a two-dimensional multi-degree-of-freedom system which corresponds to its dynamic characteristics.The stiffness matrices for vibration and control analysis is solved by the flexibility method,and the dynamic characteristics of the simplified structural model are analyzed.The period of the two-dimensional multi-degree-of-freedom system is basically consistent with that of the three-dimensional finite element model.(2)The random vibration theory and mode superposition method are used to analyze the frequency response of the observation tower,and the AR method is used to simulate the 31-dimensional correlated random process acting on the observation tower,and these samples were proved.the vibration and control analysis of tower were carried out in the time domain,the calculation results showed that response values of tower obtained from the time domain analysis are closed to those obtained from the frequency domain analysis the displacement and acceleration response of the landscape tower under pulsating wind load is mainly the first vibration mode.(3)Based on the vibration reduction target of structure,a numerical optimization design method for TMD is proposed in combination with genetic algorithm.This method fully considers the design stroke of TMD,which is superior to the traditional Den Hartog design method.Taking the actual towering structure landscape tower as an example,the effectiveness of the optimization design method of this paper is verified by the analysis of the control effect of the main structure and the dynamic test of TMD by comparing the design of TMD with the Den Hartog formula.(4)A new two-stage damping control strategy is proposed to solve the problem that the TMD travel of towering structures is too large under the action of strong wind.Taking the towering structure landscape tower as an example,the results show that under the action of strong wind,the two-stage damping TMD is switched to the optimal state of two-stage damping,which can effectively limit the displacement travel of mass block.At the same time,the control effect is the same as that of a damped TMD,and in the case of weak wind,the two-stage damped TMD is switched to the first-order damping optimal state,which is better than the first-order damped TMD.(5)Aiming at the optimization of the parameters of the TMD device designed by the numerical optimization method in this paper,TMD with eddy-current damping is designed.Firstly,the free vibration test and white noise scanning test of the model are carried out,and the basic characteristics of the model are obtained.Secondly,a large-scale shaking table model testing of the TMD seismic decrease structure using the earthquake waves of El-centro,Kobe,Taft and Synthetic harmonics is conducted.The experimental results verify the correctness of the theory. |
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