An Inclined Beam-Based Vibration Isolator Design to Attain Quasi-Zero-Stiffness Characteristics

Abstract

A linear spring element combined with a nonlinear spring element has low dynamic stiffness and high static stiffness. In this work, a quasi-zero stiffness (QZS) vibration isolator based on positive stiffness and negative stiffness characteristic is explored. Using finite element simulation, the nonlinear stiffness of the inclined beam caused by the buckling effect and the linear positive stiffness of the circular arc beam is examined. The combination of these two beams delivered high static and low dynamic stiffness. The static characteristic is performed to obtain the operational displacement range. The parametric study illustrates the effect on force displacement characteristics due to variation in thickness of circular arc beam. The dynamic characteristic of the QZS isolator is studied under different damping ratio and excitation. Additionally, a stability study is carried out to identify the frequency response curve's unstable area. Combination of inclined and circular arc beam may be a good candidate to fulfil desired requirement to achieve a wide frequency range of isolation.