Experimental and Numerical Study on Dynamic Behavior of Eddy Current Damping with Frequency Dependence

Abstract

This study investigates the dynamic and nonlinear behavior of an eddy current (EC) damping mechanism by using shaking table tests and finite-element modeling. A noncontact and friction-free EC damper is firstly designed and tested, illustrating the existing frequency-dependent characteristic. Following a primary convergence study on the mesh resolution, the three-dimensional (3D) transient analysis with the finite-element model is presented to reproduce the experimental observations, and the favorable agreement between simulation and experiment is utilized to validate the accuracy and reliability of modeling. The observations on instantaneous distribution and the phase lag of the EC are discovered and discussed. Then, a detailed parametric analysis on EC damping is further performed by evaluating the equivalent damping and stiffness coefficients generated from linear regression. The sensitivity of the two evaluation parameters on the excitation frequency and amplitude is presented with valuable insights obtained. Following that, the regressed functions of the excitation frequency for calculating the equivalent stiffness and damping coefficient are presented, and an illustrative case study is adopted to discuss the potential influence of the frequency dependence of the EC damping. Finally, the EC damper with real-size dimensions is modeled and investigated in ANSYS.