Theoretical study and experimental identification of elastic-magnetic vibration isolation system

Abstract

A vibration isolation system featuring a combination of elastic and magnetic springs and viscous and magnetic damping is presented. A mechanical flat spring houses a permanent magnet that is levitated between two stationary magnets. A prototype of the isolator is manufactured. COMSOL models are developed for the mechanical and magnetic springs. Measured data and model simulations show that the magnets arrangement results in nonlinear magnetic spring with negative linear stiffness. The mechanical spring exhibits linear behavior with positive stiffness. Experiments are performed and a nonlinear dynamic model is developed. The fabricated isolator is characterized at low and high acceleration levels. Results from model show good agreement with measured data at lower acceleration levels. Slight mismatch between model and experiment is evident at higher accelerations. This mismatch is due to the existence of lateral vibrations that are not accounted for in the unidirectional model. Results show that the combination of mechanical flat spring and magnetic spring reduces the resonant frequency of the isolator. In addition, results confirm the ability of the isolator to attenuate vibrations higher than 11.91 Hz when excited at 2.4525 [m s−2].

Investigative Study of the Effect of Damping and Stiffness Nonlinearities on an Electromagnetic Energy Harvester at Low-Frequency Excitations

“…The hardening stiffness nonlinearity can be realised by the application of magnetic springs, wherein a mass of permanent magnet is levitated between two stationary magnets [38]. However, such magnetic springs can also contribute a damping component typically referred to as magnetic damping [39].…”

Investigative Study of the Effect of Damping and Stiffness Nonlinearities on an Electromagnetic Energy Harvester at Low Frequency Excitations

“…The hardening stiffness nonlinearity can be realised by the application of magnetic springs, wherein a mass of permanent magnet is levitated between two stationary magnets [39]. However, such magnetic springs can also contribute a damping component typically referred to as magnetic damping [40].…”

Vibration analysis of a novel magnetic-viscous nonlinear passive isolator via finite element simulation

“…Mofidian and Bardaweel investigated vibration isolation systems consisting of a mechanical oblique spring with geometric nonlinear negative stiffness and a magnetic spring with positive nonlinear stiffness [15]. Also, there is a reported study on vibration isolation systems combining elastic and magnetic springs and viscous and magnetic damping [16]. Nammari et al conducted a study on a vibration energy harvester with a nonresonant magnetomechanical system [17].…”