Study On The Influence Of Friction Effect On The Damping Performance Of Pounding Tuned Rotary Mass Damper

Structural passive control device has been studied by many scholars for its simple energy consumption mechanism,simple construction and high economic benefits.Many kinds of control devices with excellent damping effect have been proposed one after another.How to enhance the applicability of each device in the project and expand its use scope needs further study.In this thesis,a new type of Pounding Tuned Rotary Mass Damper(PTRMD),which combines the advantages of fabricated cavity floor,is studied.The device combines the energy consumption characteristics of Tuned Rotary Mass Damper(TRMD)and the Pounding Tuned Mass Damper(PTMD),and has two energy consumption mechanisms of rolling tuning and collision.Installed in the large cavity of the floor system,it can be flexibly arranged in combination with the structural form and dynamic characteristics of the building,and has a wide application prospect in the project.The existing research on PTRMD energy consumption mechanism is not comprehensive,except for rolling tuning and collision energy consumption,the rolling frictional torque energy consumption of the ball vibrator and curved orbital surface has an important impact on the vibration reduction performance of PTRMD,which cannot be ignored.This thesis further introduces the frictional energy consumption mechanism,and discusses the effect of friction altogether on the vibration reduction performance of PTRMD from both theoretical and experimental aspects.The main work and results are as follows:(1)Using Lagrange principle to establish the equation of PTRMD controlled system motion,nonlinear friction force is introduced to modify the damping matrix of the controlled structure,and the energy consumption mechanism of PTRMD is changed.The frictional energy consumption law of PTRMD under free vibration,simple harmonic excitation and seismic wave excitation is simulated by numerical study.The results show that the friction effect has a great effect on the vibration reduction performance of PTRMD,and there is an optimal coefficient of friction,which makes the vibration reduction performance of PTRMD be significantly improved,which is affected by collision angle,excitation type and excitation intensity,and the friction is too small or too large to be conducive to PTRMD vibration reduction.(2)The coefficient of rolling friction between the ball vibrator and the curved orbital surface is determined by the test of rolling friction characteristics.A set of materials with different performance as friction surfaces were selected,high-speed camera technology was used to capture the movement trajectory of the vibrator on the curved orbit surface,and the vibration edge detection was carried out by MATLAB image processing function to extract the vibration spherical motion trajectory.The experiment found that the rolling coefficient of friction was related to the compactness and deformation ability of the friction material,the smaller the material compactness and the greater the deformation ability,the more obvious the elastic lag and adhesion effect of the steel ball in the rolling process,the greater the coefficient of rolling friction.(3)A single-layer PTRMD controlled frame model is designed and produced,corresponding to numerical analysis,and the dynamic response analysis under various conditions such as free vibration,forced vibration and seismic wave excitation is carried out by seismic simulating shaking table.The results show that the rolling friction energy consumption law is consistent with the numerical analysis results,and the appropriate friction coefficient can effectively improve the vibration reduction performance of PTRMD: speed up the attenuation speed of structural displacement and acceleration under free vibration,improve the adverse effect on low frequency excitation under simple harmonic excitation,and enhance the control effect of high frequency excitation.Increase the band control width under seismic wave excitation and reduce the sensitivity of the vibration reduction effect to the seismic wave excitation type.In addition,the addition of friction materials to the orbital surface can reduce the effect of rolling noise on structural comfort to some extent.