Characteristic analysis of a quasi-zero-stiffness vibration isolator

Abstract

The frequency range over which a linear passive vibration isolator is effective, is often limited by the stiffness required to support a static load. And this can be improved upon by employing nonlinear negative stiffness elements to get a low dynamic stiffness. In this paper, a quasi-zero-stiffness (QZS) system comprising an air spring with positive stiffness and Euler buckled beams with negative stiffness is studied. Compliant mechanisms are also introduced into the QZS system to achieve quasi-zero-stiffness characteristics under a variable load. Static mechanical characteristics of the system are analyzed by the FEM, and load-displacement curves and stiffness-displacement curves of the system under different working conditions are given. The natural frequency and the response curve of the system are obtained through dynamic analysis. It is concluded that the system has good vibration isolation performance in low frequency range.