Analysis and Optimal Placement of Particle Dampers Based on Discrete Element Simulation

Particle damper is formed by granular particles enclosed in a container which is attached to or embedded in a vibrating structure. The energy dissipation mechanism of a particle damper is highly nonlinear, and derived from a combination of collision/impact and friction among particles and between particles and the enclosure. Meanwhile, the coupling between particle dampers and the host structure and among multiple dampers further increases the difficulty to analyze the particle damping performance. In this paper, a new coupling method is developed to integrate the continuous host system with multiple particle dampers to analyze the energy transfer between the host structure and the dampers. The discrete element method (DEM) is employed to describe and analyze the particle motion inside each damper, which accurately accounts for various energy dissipation mechanisms of the particle damping system. In order to enhance the computational efficiency, a Verlet table combined with LC method is also used to improve the contact detection since the long time simulation is needed to perform damping analysis under a wide range of frequencies. The damping effect under different arrangements of particle dampers on a clamped-free beam is analyzed, and the results indicate that the optimal positions of dampers not only rely on the mode shape of the system, but also are dependent upon the excitation level.