Yi J., Jung W., Kim S., Kim N.

This paper describes experimental studies on the energy dissipation characteristics of viscous damping wall(VDW) and vibration control system which suppress excessive traffic-induced vibration of bridge using VDW type damper. VDW is consisted of a plate floating in a thin case made of steel and filled with highly viscous silicone oil. VDW has both viscous damping and stiffness characteristics and its viscous resisting force can be expressed as the sum of velocity dependant viscous damping force and displacement dependant restoring force. The viscous resisting force and energy absorbing capacity can be easily adjusted by changing three factors, i.e. viscosity of the fluid, gap distance and area of the wall plates. VDW was tested with a series of sinusoidal displacement history varying with different frequencies and amplitudes and the force-displacement relationship was acquired. The relationship between dissipated energy with three factors and the influence of exciting frequency on resisting force were investigated. The dominant natural frequency of bridge generally ranges between 2 and 5Hz and amplitude of traffic-induced vibration is small. The passive vibration control system was developed using the damping characteristics of VDW and was installed to bridge model. Bridge model was vertically vibrated varying exciting frequency and test results showed reduction of displacement, acceleration and stress level. Newly developed vibration control system could be easily installed in the bridge without disturbing traffic and it could improve serviceability and fatigue life of bridge with little maintenance.