A Particle Damper for Transient Oscillations\ud

Tuned vibration absorbers, in various disguises, still form the basis of vibration suppression for light and flexible structures. These simple auxiliary components may be tuned at critical frequencies of the structure to be controlled. Tuning frequencies may be constant (in case of passive absorbers) or varied (in case of semi-active and active absorbers).Tuning ensures a strong interaction, and facilitates the transfer of the harmful energy from the problem structure to the absorber. The task then becomes to dissipate the transferred energy rapidly in the absorber, before it has a chance to return the energy back to the structure. Returning the energy back to the structure, when the rate of dissipation in the absorber is not fast enough, manifests itself as a beat, significantly deteriorating the control performance. The obvious solution to avoid the undesirable beat is to include dissipative components in the design of the tuned absorber. However, such an inclusion has two consequences. First, the effectiveness at the tuning frequency is sacrificed, at a level proportional to the amount of damping in the absorber. Second, and more critically, dissipative components are high maintenance components by nature, rendering the damped tuned absorber to be less practical. A particle damper is presented in this paper which can dissipate energy rapidly while maintaining the tuning of the absorber effectively. Simple experiments are detailed to demonstrate the tuning, and the level of dissipation.\u