Research On Vibration Reduction Of Large-span Continuous Girder Bridge Based On Pounding Tuned Mass Damping

Continuous girder bridges are widely used in highways,railways and urban roads because of their good spanning performance,less joints and smooth driving.With the continuous increase of the span of continuous girder bridges,higher requirements are placed on the vibration reduction of bridges.Therefore,it is necessary to study the vibration control of large-span continuous girder bridges.Aiming at the vibration of long-span continuous girder bridges under earthquake and vehicle loads,this paper takes the long-span continuous girder bridge as the engineering background,and improves the design of pounding tuned mass damper(PTMD)on the basis of previous research.Beam-PTMD control experiments and numerical simulations are used as pilot studies to verify the PTMD numerical analysis model and analyze the vibration reduction control performance of PTMD.On this basis,the dynamic analysis model of the long-span continuous girder bridge is established,and the PTMD design parameters are optimized.Then,the vibration reduction effect of PTMD on long-span continuous girder bridges under the action of transverse seismic loads was analyzed;the vibration control effect of PTMD on long-span continuous girder bridges under vertical vehicle loads was studied.The main work and research results of the paper are as follows:1.The PTMD vibration reduction principle is discussed,as well as the differences and connections between it and the tuned mass damper(TMD)principle.The application scope,benefits and disadvantages of several collision force models are examined.Subsequently,the PTMD calculation model is determined,which is a theoretical preparation for the establishment of the seismic-bridge-PTMD coupled motion equation and the vehicle-bridge-PTMD coupled motion equation.The energy dissipation mechanism of viscoelastic material and the constitutive model of viscoelastic material are expounded,which prepares for the selection of the viscoelastic material constitutive in the following text.2.The PTMD model and test beam were designed and made,and the model test was used as a pilot study.The test beams with and without PTMD were subjected to impact load excitation respectively.The comparison of experimental results showed that the vibration reduction rate of PTMD to the peak velocity reached 21%.Subsequently,a PTMD numerical analysis model was established based on LS-DYNA,and the numerical simulation calculation was carried out on the experimental model.The calculation results were in good agreement with the experimental results,which verified the accuracy of the numerical model and provided a basis for the subsequent calculations.3.The bridge-PTMD coupling system model is established,the influence of different parameters of PTMD on the vibration reduction effect is calculated,the design parameters of PTMD are optimized,and the PTMD parameters are applied to the calculation of bridge vibration control under the action of earthquake load and vehicle load.4.The motion equation of the bridge-PTMD system under earthquake action is established,and typical seismic waves are selected for lateral seismic excitation,and the vibration reduction effect of PTMD is evaluated with the mid-span displacement,mid-span velocity,pier bottom bending moment and pier bottom shear force as indicators.5.Based on the refined vehicle finite element model,a vehicle-bridge-PTMD coupling action analysis model was established to study the dynamic response of a large-span continuous girder bridge under the action of moving vehicle loads.Computational results show that PTMD reduces the vertical vibration of bridges under moving vehicle loads;comparing the vibration response of the vehicle when driving bridge with or without PTMD,the results show that the vehicle driving more smoothly on the bridge with PTMD.