Dynamic Behavior of A Thin Plate under A Moving Magnetic Field

Abstract

This paper describes the dynamic behavior analysis of a thin conducting plate under a moving magnetic field. It is quite important to evaluate the behavior of electrically conducting structures under a moving field for the design of magnetically levitated vehicles. In this study eddy current and electromagnetic force were calculated based on a thin shell approximation using a finite element method when a coil on the plate moves parallel to the plate. Mechanical responses of the thin plate were analyzed based on a finite element method in conjunction with a modal analysis. When the diameter of the coil is almost equal to the width of the plate, the eddy current density becomes large along both edges of the plate and then the Lorentz force is large along the same parts. The dynamic behavior of the plate depends on the strength of the magnetic field produced by the coil and the velocity of the moving coil. There was found to be the critical velocity of the moving coil at which the deflection of the plate became significantly large and the vibration did not attenuate after the coil left. The critical velocity depends on the size and boundary condition of the plate.