Damping Mechanism And Experimental Study Of Pendulum Pounding Double Tuned Mass Damper

Because of its special structural form,high-rise structures often have the characteristics of low stiffness,light weight and low damping ratio.Under the action of wind,earthquake and other loads,they are prone to large-scale vibration,which affects the normal use of the structure and even endangers the safety of the structure.Therefore,the research on vibration control of such structures is particularly important.Pendulum tuned mass damper(PTMD)is commonly used in vibration control of high-rise structures.However,it has some shortcomings,such as narrow control frequency band and sensitivity to design parameters,and in practical engineering,the process of connecting damping at the bottom of pendulum makes the installation of PTMD particularly difficult.In this paper,a pendulum pounding double tuned mass damper(PPDTMD)is proposed.It combines PTMD with collision damping mechanism and designs the collision energy dissipation device inside the pendulum,which not only simplifies the design and installation of PTMD and cancels the design of external damper at the bottom of pendulum in traditional PTMD,but also due to the existence of secondary tuning mechanism in collision energy dissipation system,therefore,the damping performance of the new damper has been greatly improved.In addition,compared with the impact tuned mass damper,because the impact element of PPDTMD only exists in the pendulum,there is no sudden acceleration response due to collision during the movement of the controlled structure.In order to verify the damping performance PPDTMD,in this paper,it is studied through many aspects including theoretical derivation,numerical analysis and the suppression test,as follows:(1)This paper summarizes the development status of high-rise structures at home and abroad,structural vibration technology and various passive control devices,and analyzes the advantages and disadvantages of the current passive control devices for high-rise structures;(2)Through the theoretical derivation and numerical analysis of the ideal PTMD model and the actual engineering model,the differences between them are compared,and the influencing factors of the differences are analyzed.According to the actual engineering PTMD model,the optimal design parameters are modified.Through numerical analysis,the modified design results are verified.The modified PTMD model can achieve the best vibration reduction effect,which is basically consistent with the vibration reduction performance of the idealized model.(3)The current impact force model is analyzed.According to the research properties and requirements of this paper,the model suitable for this paper is selected and applied to the rolling impact system.Finally,it is combined with PTMD structure to form PPDTMD system.Through numerical analysis,the characteristics of PPDTMD structure are studied.(4)The motion equation of the coupling system of multi freedom structure and PPDTMD is derived.The parameters of PPDTMD are optimized based on the H_∞optimization criterion through the single degree of freedom PPDTMD system.The optimization results are compared with the traditional PTMD through the DMF curve and equivalent damping ratio of the controlled structure.Aiming at the controlled structure parameters and PPDTMD design parameters,the robustness of PPDTMD structure is analyzed.Finally,taking a self-supporting bridge tower as the research background,the actual engineering damping performance of PPDTMD is numerically analyzed through simple harmonic,earthquake,wind and other loads.(5)Through the free pendulum pounding test,the elastic recovery coefficients of different viscoelastic materials are determined.Through the rolling friction test,the influence of rolling friction on the energy consumption of PPDTMD system is analyzed.Through the PPDTMD vibration reduction test and robustness test,the vibration reduction performance of PPDTMD is verified.