Development of a design curve for particle impact dampers

Particle impact dampers (PIDs) are enclosures partially filled with particles of various sizes and materials. When attached to a vibrating structure, they dissipate energy through inelastic collisions between the particle bed and the enclosure wall, as well as between particles. In this work, the development of a design curve that can be used to predict the damping characteristics of particle impact dampers is presented. A power measurement technique enabled the time-efficient measurement of the damping properties of the PID. This technique enjoys several advantages over traditional loss factor measurements, including the flexibility to analyze the behavior of the PID at any frequency or excitation amplitude, and the ability to estimate the damping contribution for any structure operating such that the PID experiences similar conditions. Using this power measurement technique, a large number of experiments were conducted to determine the effects of vibration amplitude, excitation frequency, gap size, particle size, and particle mass on the dissipated power and effective mass of the PID. The power data were then systematically collapsed into a pair of two-dimensional master design curves with unitless axes which are comprised of combinations of design parameters. A "damping efficiency" of the PID may be predicted from the design curves for specific applications. A physical interpretation of the design curves is given, and the performance of a PID on a structure is used to verify their predictive capabilities.