Simultaneous Vibration Control Using an Impact Damper System in Horizontal and Vertical Directions

Abstract

We applied the impact damper system to the vibration model of a cantilever beam. The impact damper system consists of an impactor and walls placed in a container, which vibrates in the horizontal and vertical directions when the first and second modes of vibration are excited at the same time. The damping effects are influenced by a clearance between an inpactor and walls of a container. We changed the clearance and the acceleration of the foundation and investigated the damping characteristics of the impact damper system when the system vibrated in two directions at the same time. We calculated the vibration response of the impact damper numerically, and found that the calculation results were in accordance with the experimental ones. The impact damper system converts the vibration energy of the vibrating body to the kinetic energy of the impactor by collision. Therefore, to investigate the damping effects of two directions in the simultaneous vibration, we calculated the mechanical energy of the vibration system. We found that the damping effects of the horizontal direction were not affected by the vertical vibration when a horizontal clearance was larger than the optimum clearance. On the other hand, we found that the damping effects of vertical direction were not affected by the horizontal vibration when the impactor did not collide to the ceiling. In other words, we found that using an impactor reduced the vibrations of both the horizontal and the vertical direction at the same time when the clearance was properly adjusted.