Vibration transmissibility characteristics of smart spring vibration isolation system

NI De(倪德), ZHU Ru-peng(朱如鹏), LU Feng-xia(陆凤霞), BAO He-yun(鲍和云), FU Qiu-ju(付秋菊)

(Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology,
College of Mechanical and Electrical Engineering,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)

Abstract:The objective of this work was to study the vibration transmissibility characteristics of the undamped and damped smart spring systems. The frequency response characteristics of them were analyzed by using the equivalent linearization technique, and the possible types of the system motion were distinguished by using the starting and ending frequencies. The influences of system parameters on the vibration transmissibility characteristics were discussed. The following conclusions may be drawn from the analysis results. The undamped smart spring system may simultaneously have one starting frequency and one ending frequency or only have one starting frequency, and the damped system may simultaneously have two starting frequencies and one ending frequency. There is an optimal control parameter to make the peak value of the vibration transmissibility curve of the system be minimum. When the mass ratio is far away from the stiffness ratio, the vibration transmissibility is small. The effect of the damping ratio on the system vibration transmissibility is significant while the control parameter is less than its optimal value. But the influence of the relative damping ratio on the vibration transmissibility is small.

Key words:vibration transmissibility characteristics; smart spring; dry friction; stiffness; damping; vibration isolation; base excitation