A Study of a Ruzicka Vibration Isolator Model with High-Static-Low-Dynamic Characteristic
This paper studies a Ruzicka vibration isolator model with high-static-low-dynamic characteristic. Firstly, we analyze mechanical property of the quasi-zero stiffness spring which is composed of a cylinder and get an approximate expression of the spring’s static force. This kind of spring is the main part of a high-static-low-dynamic vibration isolator. Secondly, a Ruzicka high-static-low-dynamic vibration isolator with duffing equation is put forward, which is a combination of a Ruzicka vibration isolator and a high-static-low-dynamic vibration isolator. In the calculation process of solving its amplitude-frequency characteristic, a new method- Harmonic Equivalent Linearization Method- is used, in which the equivalent linearization algorithm is introduced into Harmonic Balance Method. This method could greatly simplify the calculation process and gives the same result as Harmonic Balance Method. Finally, the effects of additional stiffness, damping and excitation amplitude on nonlinear amplitude-frequency characteristic are investigated numerically, and also verified that the stable solutions of simulation and equation are similar. The results show that the Ruzicka high-static-low-dynamic vibration isolator is suitable for small amplitude vibration. The appropriate additional stiffness and damping ratio can change the resonance band of the amplitude-frequency characteristic curve. Therefore, the resonance can be suppressed by controlling the initial state of vibration.