Energy dissipation characteristics of particle dampers with obstacle grids

Abstract

When the vibration excitation intensity is high, the energy dissipation of conventional particle dampers (PDs) is low. The experiment result shows that the three-dimensional grid structure (obstacle grids) in the particle damper can improve the problem of low efficiency of energy dissipation. In order to investigate the influence of obstacle grids on the particles motion and energy dissipation, a numerical model of a particle damper with obstacle grids is established by the discrete element method (DEM). The simulation results are basically consistent with the experiment results. The influence of vibration parameters and filling ratio on the energy dissipation is studied. The spatial distribution characteristics of particle collision and energy dissipation inside the particle damper are discussed. Under frequencies of 30–160 Hz, excitation intensity Γ > 5, and filling ratios of 50–90%, results show that the obstacle grids will change the motion behavior of the particles and enhance their energy dissipation. Under this condition, the obstacle grids make the particles, which originally do not contribute significantly to energy dissipation, to agitate aggressively and participate in energy dissipation. It means that particles in the bottom space of the damper have the multiplicative collision frequencies characteristics in one vibration cycle, thus increasing energy dissipation.