Damping Performance of a Particle Damper in Two Dimensions

Particle damping is a technique of achieving high structural damping with small metallic particles embedded within a cavity that is attached to the vibrating structure at the location of high vibration amplitudes. In this work, a simple yet detailed analytical model that takes into account normal as well as oblique impacts is presented to study particle damping in two dimensions under transient vibrations. The focus of the research presented here is to determine the role of major energy dissipation mechanisms such as friction and impact phenomena involved in particle damping in context of varying two dimensional cavity sizes. Particle damping is measured experimentally for an L-shaped beam in a fixed free configuration with a cavity attached at the top free end to investigate the effect of cavity size on its performance. It is observed that the peak value of the damping is mainly influenced by the cavity size in vertical direction, but the increase in cavity size in horizontal direction, makes this peak even bigger and shifts it slightly towards lower dimensionless acceleration amplitudes values. It has been found that normal impact phenomenon remains dominant in energy dissipation but the role of impact friction becomes very important and effective in the vicinity of peak specific damping capacity value with the increase in the size of the cavity. The model predictions regarding the effect of particles to structure mass ratio on the performance of particle damper are also in agreement with the reported data in the literature.