Research On Damping Mechanism And Application Of Vertical Pounding Tuned Mass Damper

As one of classic passive control technology,the tuned mass damper(TMD)has received widespread acceptance and applied in the field of vibration control with its simple construction and low maintenance cost.However,there are still some defects,such as sensitivity to frequency,poor adaptability to excitation,which results in the unstable control effect of TMD in practical work.What's worse,The huge mass block takes up large space and makes it inconvenient in installation.Box section is always applied in long-span pedestrian bridge,which makes TMD to be difficult to apply in the overpass vibration control.Based on the pedestrian bridge,the proposed pounding tuned mass damper(PTMD)is studied to control vibration of bridge.Unlike traditional tuned mass damper(TMD),viscoelastic material is used to give pounding tuned mass damper(PTMD)pounding energy dissipation mechanism,which can absorb energy through collision between mass block and viscoelastic material.The main work and achievements are as follows:(1)Vertical pounding tuned mass damper device is designed and produced based on the vibration reduction principle.The finite element model of PTMD is created and its working characteristics are studied.(2)Based on the crowd load model and the improved collision force model,the dynamic response of the pedestrian overpass under the control of no control,TMD and PTMD was obtained through numerical analysis.The numerical analysis shows that the displacement damping ratio of the PTMD on the pedestrian flyover is 11.02%higher than the TMD,and the vibration damping rate of the acceleration is increased by 10%,indicating that the control effect of the PTMD is better than that of the TMD.Then the parameters of PTMD were studied and analyzed,and the influence of different parameters on the effect of vibration control was obtained.With the increase of mass ratio,the effect of vibration reduction was increased,and the optimal impact clearance provided the best effect of vibration reduction.The MPTMD control system has better damping effect than PTMD,and it also reduces the weight of the PTMD mass.Finally,the main parameters of the MPTMD are studied and analyzed.(3)Testing the vibration control effect of PTMD.Designing and producing a test beam based on the dynamic characteristics of the pedestrian bridge.Then installing the PTMD damper on the test beam.An artificial excitation was applied to the test beam.The test results showed that the damping rate of the peak acceleration of PTMD increased by 9.52%compared with TMD,and the damping rate of the acceleration mean square value increased by 11.78%,indicating that the control effect of PTMD was better than that of TMD.After that,the parameters of PTMD were analyzed through experiments,and finally the effects of vibration control of MPTMD system were studied.