Damping of Rotating Beams with Particle Dampers: Experimental Analysis

The main objective was to determine the performance of a particle damper under centrifugal loads. A test bench was developed, consisting of a rotating cantilever beam with a particle damper at the tip. Equal mass containers with different depths, tilled with a range of uniform-sized steel ball bearings, were used as particle dampers. For all the tests, the total particle damper mass was identical. During operation, the tip of the beam was displaced, and after release the beam could vibrate freely. The decay in the vibratory motion of the tip of the beam was measured over a range of centrifugal loads. It was found that there is a zone with a high- and one with a low-damping factor. These zones depend on the ratio between the peak vibration acceleration and the centrifugal loading and have a limit, in terms of the centrifugal loading beyond which no damping occurs. The main parameters that influence the performance of the particle dampers are the length/diameter aspect ratio and the particle size. An important finding is that a particle damper with fewer layers (increase in particle size) will still function at a higher centrifugal load, compared with one with more layers.