Nonlinear vibration isolation via a circular ring

A novel nonlinear vibration isolator in the shape of a circular ring is investigated in this study. When the ring is compressed along a diametral line, it exhibits highly nonlinear geometric stiffness due to the effects of stretching-induced tension coupled with the curvature changes. The use of stiffness nonlinearity improves vibration isolation efficiency. A mechanical model of the ring under compression is derived from beam theory. Methods of direct separation of motions and harmonic balance are employed to determine the frequency response and displacement transmissibility of the device under base excitations for different geometric configurations. The analytical results are numerically validated via direct time integration of the equation of motion and via experimental data. It is shown that an increase in the pre-deformation of the ring enhances the vibration isolation performance.