Examination of Particle Behavior in Container on Multi-Particle Collision Damper

Abstract

Recently, impact dampers have been used to decrease the vibrations of objects. One specific case of a damper is a container filled with many spherical particles. Compressive forces, frictional forces, and impacts are generated between particles and the wall. Therefore, it is important to clarify the flow conditions of particles in order to investigate the appropriate damping conditions. However, it is difficult to experimentally observe and to calculate the complex behavior of particles in such a container. In this study, the behaviors of particles in a container of a particle damper were examined through experiments using piezoelectric elements and simulations performed by the discrete element method (DEM). Many spherical particles fill a container. The container is made to periodically move in a horizontal direction. The relationships between the collision of particles with the wall and the voltage value from the piezoelectric element were examined. With these calculations, particle behaviors and particle conditions can be analyzed. The behaviors of simulated particles were similar to those of experimental results. From both results it is shown that an appropriate selection of the filling ratio and of particle size will lead to the effect of particles for damping.

Effect of particle damper under torsional vibration

“…Discrete Element Method)がある(Cundall and Strack, 1979) ． 著者も個別要素法を用いて種々の解析を行ってきた．例えば，遊星回転する容器内の粒子群の挙動について，多 角形断面の容器を用いて解析(高橋他，2003) ，遠心力の影響について検討(高橋他，2010)を行い報告した．ま た， 粒状体ダンパの容器内の粒子の流動状態について圧電素子を用いて検討も行った(Takahashi and Sekine, 2015) ． そこで本研究では，図 1 に示すように容器内に粒子を充填した系における Y 軸まわりのねじり振動に着目し， Contact condition of two particles. The coordinate system is shown in thisfigure.…”