Internal Resonance of a Rotating Magnet Supported by a High-Tc Superconducting Bearing

This research deals with nonlinear dynamics of a rotating magnet levitated above a high-T_c superconducting bulk. Under no contact support by magnetic force, the magnet levitates stably without control. Such a low-damping system can show complex dynamical behaviors, because of nonlinearity of the magnetic force. In multi-degree-of-freedom nonlinear systems one can find energy transfer between modes through nonlinear coupling, which is called internal resonance. In this research, mechanism of the internal resonance was discussed from the equations of motion. This resonance was confirmed by numerical analyses and experiments.