Study on design method of floating slab vibration isolator with high static and low dynamic stiffness characteristic

Here, based on load characteristics analysis of floating slab vibration isolator, the optimization design goal of vibration isolator was proposed. Based on the nonlinear vibration isolation theory, the nonlinear stiffness curve with high static-low dynamic stiffness characteristics was designed, and its static characteristics and dynamic ones were analyzed. Aiming at defects of the designed nonlinear stiffness curve, the vibration isolator' s optimal damping curve to match them was designed to further improve its vibration isolation performance. Through nonlinear design of stiffness and damping parameters of the vibration isolator for floating slab track, the vibration isolator could have abilities of lower frequency vibration isolation and dynamic displacement control. The theoretical study showed that compared with the linear vibration isolator, the designed nonlinear vibration isolator has the lower main resonance frequency, and its resonance peak is significantly lower than that of the former; compared with the floating slab vibration reduction track system with existing linear steel spring vibration isolator so called the linear system, the floating slab vibration reduction track system with nonlinear vibration isolator can effectively control dynamic displacement of track slab, and the dynamic displacement of track slab can be reduced by about 50%; the latter can significantly reduce vibration acceleration response of track slab, and the effective value of vibration acceleration can be reduced by about 46%; its vibration isolation effect in low-frequency band ( ≤ 20Hz) is better than that of the linear system, especially, at about 10 Hz, the latter' s vibration decay effect is the most obvious, and the frequency division' s maximum vibration level insertion loss can reach 11. 83 dB. © 2022 Chinese Vibration Engineering Society. All rights reserved.