Development and Application of a Dynamic Theoretical Model for the Eddy Current Dampers Based on Mechanical Experiment

Abstract

Eddy current damper (ECD) has emerged as a highly desirable solution for vibration control due to its exceptional damping performance and durability. However, the inherent nonlinearity of the ECD poses significant challenges in research and engineering implementations. Traditional views attribute the nonlinearity of the ECD solely to variation in velocity. However, experimental results reveal that nonlinearity still exists even at a constant velocity. The nonlinearity at a constant velocity has not been sufficiently emphasized and quantitatively modeled. This study addresses the issue by developing a dynamic theoretical model with clear physical meaning and a simple mathematical form. A comprehensive study of the nonlinear characteristics of the ECD has been carried out using a combination of experimental and theoretical analysis. Firstly, the basic construction and working mechanism of a velocity-amplified hamburger-shaped eddy current damper (VHECD) are described in detail. Subsequently, a prototype experiment is conducted to explore the mechanical performance of the VHECD. Most importantly, a nonlinear phenomenon at a constant velocity is revealed and a dynamic theoretical model is developed. Finally, the dynamic theoretical model is validated through the experimental results of the VHECD and numerical simulation of a single-degree-of-freedom (SDOF) system. The proposed dynamical theoretical model generalizes the nonlinear phenomenon at a constant velocity. Both the coefficient of determination of force and the mean absolute percentage error of energy dissipation show that the dynamic theoretical model performs exceptionally well. The numerical simulation of the SDOF system demonstrates that the proposed dynamic theoretical model can more accurately predict the damping performance of ECD than the Wouterse model. This dynamic theoretical model is useful for the physical understanding of the ECD and the engineering application.