Theoretical and experimental studies on vibration attenuation for squirrel cage by metamaterial belt structure

Abstract

For the squirrel cage in aero-engine, a metamaterial attenuation structure is presented to control its vibration. Considering the characteristic rotating speeds of rotor system, several types of metamaterial cells are designed. According to the shape of squirrel cage, a structure composed of the metamaterial belts is designed to realize vibration attenuation. For each cell, the dispersion analysis is carried out. The results prove that the bandgap could cover the characteristic frequency of the rotor system. For the squirrel cage equipped with the metamaterial belts, corresponding Finite Element Method (FEM) model is established and simulations are carried out. The results prove that the metamaterial belts could attenuate the cage’s vibration effectively. The validation experiments were carried out. The results of sweeping frequency prove that the metamaterial structure could attenuate the vibration amplitude significantly. Especially, at the resonance frequency, the squirrel cage with metamaterial belts could reach a 96% reduction in amplitude compared to the squirrel cage without it. The responses for harmonic excitations prove that at the characteristic rotating speed the vibration amplitude of squirrel cage can be reduced greatly. The results may provide a guidance for the design of vibration attenuation of squirrel cage.