Enhancing Structural Seismic Resilience with a Novel Variable Damping Inertial Eddy Current Damper

Abstract

Eddy current damping has the characteristics of non-contact, easy adjustment, convenient processing, and high energy dissipation efficiency. Combined with the damping enhancement effect of inerter systems, it is conducive to further improving its damping effect. This study proposes a novel Variable Damping Inertial Eddy Current Damper (VD-IECD), which generates fixed damping force through permanent magnets and variable damping force through electromagnets. Using Statistical Linearization Techniques (SLT) and equivalent criteria based on force and energy, the equivalent damping ratio of the eddy current damping can be calculated. Two optimal design methods for using IECD in tuned vibration control are presented. Subsequently, a numerical comparative analysis was conducted between IECD and Tuned Inertial Eddy Current Damper (TIECD) with traditional Linear Viscous Dampers (LVD) and Tuned Viscous Mass Dampers (TVMD). The results show that VD-IECD performs better than LVD in terms of vibration control and energy dissipation. By adopting a switching control strategy based on elastic displacement limits, VD-IECD further enhances the seismic performance of structures. TIECD shows good control effects on displacement response. However, due to the nonlinear characteristics of the eddy current damping force, TIECD has negative effects on velocity and acceleration control. This study highlights the potential of VD-IECD in improving structural resilience against seismic events, providing an innovative solution for effective energy dissipation and structural protection.

Keywords: Inerter, Eddy Current, Variable damping, Semi-active control