Abstract

Cyclic structures are rotationally periodic arrays of (almost) identical sectors that can be found in many engineering applications, such as bladed disks in turbomachinery. In this talk, we are going to explore the effectiveness of vibro-impact absorbers in mitigating the near-resonant forced vibrations of cyclic structures. A vibro-impact absorber is a small mass (typically spherical) that freely sits inside a cavity in the primary structure where it undergoes frequent impacts with the cavity walls. It was recently shown that these impacts scatter energy to higher off-resonant modes of the structure, which are able to dissipate the energy on a much faster timescale than the resonant vibration. The high effectiveness of vibro-impact absorbers for mitigating near-resonant vibrations has so far only been shown for non-cyclic/non-periodic structures. When applied to cyclic structures, however, we will show that vibro-impact absorbers cause numerous co-existing states of vibration that the structure can possibly exhibit. While some of these states are favorable for vibration mitigation, others are characterized by a strong localization of energy in just a few sectors. We will attempt to answer whether these strongly localized vibrations would be harmful to our cause of mitigating the vibrations or not.