Buckling-Induced High-Static-Low-Dynamic Stiffness Vibration Isolator With Semiactive Nonlinear Damping

Existing high-static-low-dynamic stiffness (HSLDS) isolators typically use three springs, magnets, X-structure, or origami to achieve low-frequency vibration isolation. This article proposes a novel design that leverages buckling-induced deformation to achieve HSLDS, combined with semiactive electromagnetic shunt damping for enhanced vibration isolation performance. Finite element analysis is used to study the deformation characteristics, bistability, and mechanical properties of the buckling stiffness component (BSC). A specific electromagnetic shunt circuit, consisting of two magnets and a pair of coils wound in opposite direction, enabling semiactive nonlinear damping, is proposed. The nonlinear electromagnetic coupling coefficients are derived. The vibration isolation performance is examined using the harmonic balance method. Results demonstrate that when relative rotation occurs between the inner and outer rings, bending deformation of the curved beams is induced, which leads to the BSC reaching second stable state. Consequently, HSLDS is generated in the axial direction, facilitating low-frequency vibration isolation. The damping strength adjusts with relative displacement, enhancing resonance damping and minimizing isolation deterioration, consequently, improving isolation performance across the entire frequency range. This article offers new insights into designing HSLDS-based vibration isolators and achieving nonlinear damping.