粒状体を用いた転動型制振装置の開発

抄録

Passive vibration dampers are very efficient solution for vibration control in structures with low natural frequencies. However, conventional dissipative elements used in their dampers require maintenance due to their nature of their function. Therefore, it is necessary to develop a virtually maintenance-free dissipative element. In this study, a tuned rolling-granular damper is presented. This damper consist of a cylinder partially filled granular materials, which rolls in a cylindrical surface attached to a primary system. In this damper, the granular materials is the energy dissipating agent. Granular motion induced inside the cylinder, consists of intermittent contacts with other particles and the wall of the cylinder. It results in the rapid energy consumption. The effect of the particle size and mass ratio on the damping performance was investigated experimentally. The granular materials used in this study were steel particles and are of uniform size. By means of the discrete element method (DEM), an analytical solution is provided to estimate the damping performance. The contact force acting on the rolling cylinder is modeled by the sum of the spring force based on Hertzian contact theory and the damping force introduced by Tsuji. Comparison between the theory and the experiment was found to be good.