Research On Bridge Vortex-induced Vibration Control With PTMD

In a variety of wind-induced vibrations of bridge,due to lower wind speed,vortex-induced vibrations often appear in the stage of the construction and the finished of the large-span bridges.Although the vortex vibration will not directly cause the structural dynamic instability damage,the continuous vibration will easily cause the fatigue damage of the bridge structure and affect the service performance such as driving comfort and stability.Therefore,the vortex-induced vibration is an important part of the wind resistance design of the bridge.The pounding tuned mass damper(PTMD)is a new type of passive dampening device,which adds a baffle to limit the TMD displacement on the basis of the TMD,and sets a layer of viscoelastic materials between the baffle and the mass,and makes use of the force of the inertial and impact for structural vibration damping.Based on the review of the current research on Vortex Vibration and PTMD of bridges,this paper studies the application of PTMD to control the Vortex Vibration of bridges.The main research works done are as follows:(1)The basic theory of vortex induced vibration of the bridge is introduced.Based on the actual bridge,a 1:40 bridge segment model was made and the wind tunnel test was carried out.Based on Scanlan’s empirical linear model and harmonic force model,the "half-bandwidth method" and the least squares method were used to identify the parameters of the vortex-induced force model under each wind speed.(2)The steel-viscoelastic material collision test was carried out.Based on the nonlinear characteristics of the collision and a new type of impact force model,the parameters of the impact force model were identified through the test data analysis.(3)The structure-PTMD coupled dynamic model was established,the damping performance of PTMD under the influence of vortex-induced force was analyzed by MATLAB simulation,and the influence law of mass ratio,frequency ratio,damping ratio and other parameters on the vibration damping effect was also studied.(4)The bridge segment model-PTMD system was designed to carry out wind tunnel test and study,and the damping effect of PTMD with different quality parameters,frequency parameters and damping ratio parameters were obtained.At the same time,the damping performance of different viscoelastic materials and the control robustness of PTMD were also studied in detail,and the vortex-induced vibration damping performance of the PTMD was fully evaluated.