关键词: 薄壁盘, 电涡流阻尼, 动力学, 永磁铁, 振动抑制

Abstract: Thin-wall components, featured with light weights and high strength, have been widely employed in aeronautics and aerospace applications. However, thin-wall workpieces during machining are easily subjected to deformations and vibrations due to small stiffnesses, which renders poor dimension precisions and surface qualities of final products. For reducing multi-modal vibrations of thin-wall workpieces during machining, a non-contact design of an eddy-current damper is proposed. Firstly, the coupled dynamic model of a thin-wall plate and an eddy-current damper is established to capture the distributed system parameters of inertia, damping and stiffness in both the time and spatial domains; the linear relation between the eddy-current damping (ECD) and vibration displacement is obtained via modal dimension reduction and local linearization of the physical model. Numerical examples are employed to analyse the effective area of the eddy-current distribution, investigate the effects of dimension and location of the permanent magnet on the ECD, and simulate dynamic behaviours of the thin-wall plate coupled with the ECD, which provides fundamentals for designing the eddy-current damper. Finally, the theoretical model and simulation analysis are validated by the step-response and lathe-machining tests on the coupled system, through which the effectiveness of ECD on vibration suppression for a thin-wall plate is illustrated. The proposed ECD method provides a simple yet practical solution for vibration reduction in thin-wall component machining.

Key words: dynamics, eddy-current damping, permanent magnet, thin-wall plate, vibration suppression