Nonlinear dynamics and vibration reduction properties of a quasi-zero stiffness magnetic isolator under translational and rotational coupling excitation

• Considered the vertical and rotational coupling excitation. • The nonlinear dynamic responses under coupling excitations are investigated. • Analyzed the influence of nonlinear effects on vibration isolation performance. • The static deformation and resonance frequency of the vibration isolator are reduced. To suppress both vertical and rotational vibrations, a quasi-zero stiffness (QZS) vibration isolator is proposed. The device uses the magnet pair’s hardening stiffness to compensate for the X-shaped structure’s negative stiffness. The comparative validation is completed by comparing the simulation results of ADAMS and COMSOL. The device’s dynamic characteristics are systematically analyzed. The numerical analysis results show that a) under coupling exactions, the proposed isolator may perform rich nonlinear dynamic responses such as hardening nonlinearity, jump phenomena, loop phenomena and the super-harmonic resonance; b) in terms of the force transmissibility, the nonlinear effect produced by horizontal damping have more desirable vibration isolation performance than the linear vertical damping; c) compared to a conventional QZS isolator compensated by a linear spring, the proposed device has a low resonance frequency, slighter offsets, and reduced static deformation .