Analytical and experimental study of Eddy current damper for vibration suppression in a footbridge structure

Abstract

Eddy current damping has been extensively developed in recent years and is widely used in the mechanical engineering sector, for example, in railway and turbine braking systems as well as in car vibration control systems. Vibration control approaches for civil engineering structures still usually rely on more traditional approaches, such as viscous and tuned mass dampers. The use of novel Eddy current damping devices has the potential to complement these traditional approaches and is the focus of the work presented here. The Eddy current damper (ECD), which is a kind of electromagnetic induction damper, comprises a permanent magnet, a conductor and framing components. In this study, an ECD is developed and investigated to provide an alternative to viscous dampers that often exhibit undesirable non-linear characteristics arising from friction. Since the moving components of an ECD are not in contact, the influence of friction is negligible. A finite element model is initially used to evaluate the ECD damping properties and employed on a footbridge structure. The finite element and analytical results demonstrate satisfactory augmentation of damping effect under both random and harmonic signal input.