Characteristic analysis of a new high-static-low-dynamic stiffness vibration isolator based on the buckling circular plate

Zhirong Yang,Ziming Huang,Zhushi Rao,Yan Wang

doi:10.1177/1461348420904864

Abstract

The high-static-low-dynamic stiffness vibration isolator has great advantages in vibration isolation because it can decrease the natural frequency of the system while keeping the load capability, but it is usually difficult to implement because of its complex structures and installation space constraints. A high-static-low-dynamic stiffness vibration isolator composed of a buckling circular plate and a traditional linear spring is proposed in this paper. The buckling circular plate works as the negative stiffness corrector paralleled with the linear spring, which can be integrated into the sleeve. If the load is chosen properly, the static equilibrium point will be at the initial quasi-zero stiffness point. However, any changes of the load will lead the equilibrium point deviating from the initial equilibrium point. The nonlinear mathematical model of high-static-low-dynamic stiffness vibration isolator considering load imperfection is developed and its force transmissibility is analyzed with the harmonic balance method and homotopy perturbation method. The influence rule of the system parameters on it is analyzed and the corresponding results show that the force transmissibility will exhibit complicated characteristics, depending on the load imperfection, damper, and excitation force.

Highlights

The passive isolation technology is the most common approach to attenuate the harmful vibration because it is much easier to realize than active isolation and does not require the external power source
The force transmissibility of the high-static-low-dynamic stiffness (HSLDS) vibration isolator working under overload conditions using a buckling circular plate as the negative stiffness is discussed in this paper
They both indicate that the peak value of force transmissibility can be reduced when the excitation force amplitude decreases or the damping ratio rises under rated load conditions

Summary

Introduction

The passive isolation technology is the most common approach to attenuate the harmful vibration because it is much easier to realize than active isolation and does not require the external power source. It is alspoffiffiknown that the traditional linear passive isolator only works when the excitation frequency is greater than 2 times the resonance frequency of the system.[1] The frequency range of isolation would be expanded if the resonance frequency of the isolator is reduced, which can be achieved by decreasing the stiffness or increasing the mass of the system. It is usually hard to adjust the mass of the system, so the declining stiffness of the isolator and adjusting the corresponding damping ratio are general methods to reduce the vibration. If the stiffness of the isolator is quite low, the static deformation would exceed the space limitation. High-static-low-dynamic stiffness (HSLDS) vibration isolation systems built by combining the negative stiffness structure and a linear isolator have been developed to overcome this contradiction.

Objectives

Conclusion