Novel Universal Multistable Mechanism Based on Magnetic–Mechanical–Inertial Coupling Effects

Different from multistable mechanisms incorporating multiple bistable elements, a novel universal multistable mechanism possessing the capability of being triggered in all in-plane directions was first designed and fabricated by using symmetric 3-D magnetic structures, which mainly consists of one magnetic ring supported by a elastic rod and one axially magnetized pillar fixed on the aluminum case. The in-plane isotropic multistability was originated from the nonlinear interactions among the inertial force, the elastic force, and the magnetic force. According to the pseudo-rigid-body model and magnetic charge model theories, an accurate mathematical model was established for precisely analyzing the nonlinear magnetic-mechanical-inertial coupling mechanics. By considering the influence of the translational motion and the inclination angle of the magnetic ring on the magnetic field distribution and strength, the nonlinear force versus displacement relationship was obtained numerically and experimentally. The numerical results are in good accordance with those obtained by experiments, thus validating the design methodology for isotropic multistable mechanism.