Numerical and experimental investigations in the damping behavior of particle dampers attached to a vibrating structure

Particle damping is a passive damping technique at which granular material is either filled in a box attached to a vibrating structure or it is filled in holes embedded in the vibrating structure. Due to the structural vibrations, momentum is transferred to the granular material which interacts with each other. As a result, energy is dissipated by impacts and frictional phenomena between the particles. In this paper, a discrete element model is combined with a reduced finite element model. It can be analyzed for a wide frequency range. The accuracy is validated by experiments. The testbed consists of a beam with a free-free boundary condition excited by a shaker and its velocity profile is measured with a laser scanning vibrometer. The particle damper is filled with different steel balls. The discrete element code uses continuous contact models. An efficient contact algorithm is used while a coupling with a finite element model of the structure enables the prediction of the overall system movement. The system is analyzed over a wide frequency range for multiple eigenmodes. The first comparisons of experiments and simulations are performed showing a good agreement of the frequency response and modal parameters. A high dependency of the damping on the position of the particle box and its filling ratio is obtained. (C) 2020 Elsevier Ltd. All rights reserved.