Vibration property dependence on the trapped flux of a bulk high-temperature superconductor

Vibration properties are investigated in the stable suspension between a permanent magnet (PM) and a bulk YBaCuO magnet at 77 K. The bulk YBaCuO is magnetized by a controllable electromagnet. Experiments and analyses show that a PM can just suspend under the YBaCuO magnet at certain magnetization conditions of a high-temperature superconductor (HTSC). In this paper, the stable suspension happens when the ratio is set as 0.1-0.29 between the maximum trapped field and the maximum field of the PM. The resonance frequency increases with the increment of the trapped field, that is, a 'stronger' HTS magnet results in a higher resonance frequency as well as larger dynamic stiffness. However, transmissibility dependence on the trapped field of an HTSC magnet goes to an inflexion of 41.37 dB at 0.065 T maximum trapped field in the HTS magnet, which brings a small damping and instability. These relationships are helpful in improving the mechanical and levitation performance of some high-temperature superconducting magnetic levitation systems