Vibration reduction of a high-T_c superconducting magnetic levitation system with an autoparametric vibration absorber

This research proposes reduction in the amplitude of a primary resonance generated in high-T_c superconducting (HTSC) magnetic levitation system using an autoparametric vibration absorber. In general mechanical systems, reduction of the primary resonance or some nonlinear oscillations have been successfully studied using a kind of a nonlinear vibration absorber called an autoparametric vibration absorber through nonlinear coupling, which is called internal resonance. In this study, we assume that the rigid body vibrates only in the vertical direction z. On the rigid body a pendulum is fixed as an autoparametric vibration absorber. Through the nonlinear coupling that is generated, the amplitude of z is reduced. The governing equations in z and 9 directions are derived, and the possibility of energy transfer due to internal resonance is suggested. From the equations, analytical results predict that the amplitude of z decreases when internal resonance occurs. Numerical results confirm this prediction.