Experimental Research of an Anisotropic Gyroscopic Rotor with Non-linear Elastic and Damping Characteristics of the Support

This research experimentally investigates the effect of anisotropy of non-linear restoring and damping characteristics of elastic support on the dynamics of a vertical gyroscopic rotor. The research results show that in the case of asymmetry of the stiffness of the support in opposite directions, one critical velocity is observed when the vortex accelerates, and another, larger critical velocity with a lower resonant amplitude, is observed when the rotor vortex slows down. When replacing a viscoelastic material having some viscoelastic properties with a similar material having other similar properties, the suppression of the amplitude of rotor vortex in resonant areas and areas beyond critical speeds proves that the support materials have properties of cubic non-linear damping, in addition to linear damping. In addition, viscoelastic materials are characterized by the nonlinearity of their stiffness in the direction where the vortex slows down. In the areas of the first and second critical velocities, two elevations of amplitude characteristics are observed in each of the two perpendicular directions. The magnitude of the elevation with a lower amplitude is related to the magnitude of the gyroscopic coupling. The nonlinearity of stiffness was also manifested in the case of anisotropy of the viscoelastic properties of the support structure in orthogonal directions. The experimental resonance curve built agrees with a similar curve built according to the analytical formula of the amplitude characteristic of a gyroscopic rotor.