Transient Analysis Method of an Axially Magnetized Novel Passive Eddy Current Damper for Suppressing Lateral Vibrations

A passive eddy current damper (PECD) can be adopted to provide a damping effect and drag force in rotating structure applications. The damping effect is formed as the result of induced eddy current, while the drag force is produced as the result of the repulsive force between the same axially poled magnets. However, modeling and approximating the damping effect, repulsive force, stiffness, the magnetic flux density (MFD) distribution, and eddy current prompted in PECD is a challenging task because of the complicated structure and operational conditions. This paper presents a new method for modeling and estimating the dynamic parameters of novel PECDs such as the damping effect, repulsive force, and stiffness for suppressing vibration in rotating structure applications. This self-powered, cost-effective PECD utilizes four arc-shaped and single ring-shaped permanent magnets with a cylindrical conductor placed between the arc magnets and the ring magnet to generate a damping effect and spring. Eddy currents are generated in the cylindrical conductor as the effect of the relative motion of the ring magnet concerning the arc magnets. An accurate and transient analysis method of the proposed system is carried out by using a three-dimensional finite-element method (3D-FEM). According to the procedures applied in the FE model solution, this new numerical method is appropriate and validated for analyzing PECDs and gaining good results by configuring the conductor and permanent magnets symmetrically. Finally, this novel 3D transient analysis method presents a perfect ability and accuracy for both modeling and calculating the PECD parameters.