Dampening of a cantilever beam with large particles in a small cavity: model and experiment

Particle dampers are passive attenuating mechanisms of vibration, where small-sized particles (less than 1 mm in diameter) are introduced into the structure to dissipate energy by shock and friction. For that, we must have enough space in the cavity for the particles to move, which usually requires large cavities in relation to the size of the particles. In this work, the idea is to reduce the volume of the cavities, thus reducing the required space for the damper in the structure. As a consequence, we increase the mass of the particles to improve the performance of the damper (stainless steel spheres of 5 mm diameter) and the spheres are free to vibrate inside the structure within a small gap in the cavity (0.1 mm total gap). The shock of the spheres against the walls of the cavity in the structure dissipates energy within this small gap. We present a mathematical modeling of the system, and we correlate it with experimental results. The results show a significant reduction of the resonance peak with the use of the damper even in the case of such a small space for the motion of the sphere.