Optimal design of tuned inerter eddy current damper

Abstract

The tuned inerter eddy current damper (TIECD) is a vibration absorber for seismic protection of structures. This paper studies the dynamic characteristics of the TIECD and investigates its optimal design considering the nonlinear behavior of the eddy current damping (ECD). The relationship between the nonlinear parameters of the ECD and its equivalent damping coefficient is revealed by utilizing the energy equivalent linearization method. The optimal design formulae for a TIECD are derived. The comparisons indicate that the proposed solutions offer an ideal estimation for the TIECD optimal design parameters of a lightly damped structure. In contrast with the linear tuned viscous mass damper (TVMD), the nonlinear TIECD achieves better control performances. However, the fluctuation in dynamic loads for the TIECD-structure system could lead to some special nonstationary motions. For the natural ground motions, a practical iterative design procedure for the TIECD is proposed. The results show that the control performance of the TIECD can reach the level of the TVMD with lower maximum damper forces.