Design, dynamics, and dissipation of a torsional-magnetic spring mechanism

We present an analytical and experimental study of a torsional magnetic spring where the restoring torque results from field interactions between rotating fixed permanent magnets (PMs). The cylindrical PM, called rotor, is supported on ball bearings two magnets, stators. Perturbing rotor its equilibrium angle induces whose effect ressembles spring. Along with this effect, dissipation mechanisms arise structural viscoelasticity, air, electromagnetic damping, friction in bearings. To investigate dynamic these mechanisms, we construct setup capable mechanical, electrical, measurements. For various rotor–stator gaps setup, validate model that assumes viscous dry (Coulomb) damping during rotor’s free response. Moreover, force by coil into high amplitude oscillations. observe unusual resonator’s nonlinearity: at large rotorstator gaps, oscillations are softening; reduced stiffen-then-soften. developed reduced-order models capture nonlinear effects rotor-to-stator rotor-to-coil distances. These oscillators promising for low-frequency signal transmission designing magneto-elastic metamaterials tailorable nonlinearity.