Design And Analysis Of The New Quai-Zero-Stiffness Isolator

At present, the low-frequency vibration isolation is still a major problem in the field of mechanical engineering.Therefore, design of a effective low-frequency vibration isolator is very important. Quasi-zero-stiffness (QZS) isolator, consisting of elastic components with positive and negative stiffnesses, possesses zero stiffness at the static equilibrium position, and large stiffness when the deflection is relatively large. Hence, this kind of isolator can effectively isolate low-frequency base oscillations.This paper presents a prototype of a buckling plate vibration isolator with the propitious characteristic of quasi-zero stiffness (QZS). The isolator is devised by combining a rubber pad with a buckling steel plate. To facilitate the analysis of the characteristics of the QZS isolator, an approximate expression of force and displacement is formulated based on Abaqus analysis and Matlab tool. Analytical result reveals the stiffness criterion of the supporting rubber for the QZS system. The force transmissibility of the vibration isolation systems is derived by the harmonic balance method (HB), and the effects of the damping, stiffness, excitation amplitude are investigated for the performance evaluation of the systems. The results show that the QZS isolator can outperform the linear system in low frequency domain, and no involvement of resonance when damping is set properly.The static test of the buckling plate quasi-zero stiffness vibration isolator is conducted. The quasi-zero stiffness platform and the structural parameters of the system are got. The dynamic experiments of linear isolator and quasi-zero stiffness isolator are carried out on the vibration test stand, and the force transmissibility curve of them are found. By comparing the experimental results, it is found the buckling plate quasi-zero stiffness isolator is better than the linear systems. And in the experiment, the force transmissibility curve of the buckling plate quasi-zero stiffness vibration isolator appeares jump phenomenon,the jump interval is0.6Hz, it verifys the theoretical analysis.