A railway isolator to preserve the fundamental frequency analysis and test

摘要

Isolators have become more attractive to researchers and industries alike over the past decade. Nonlinear stiffness for the rubber isolator is designed in the floating slab system to obtain or maintain the desired natural frequency. According to the vibration mechanics theory, the natural frequency formula can be deduced backward to obtain the function of stiffness. This then yields a simple integral equation which can be reduced and solved as an ordinary differential equation. The results demonstrate that using the nonlinear isolator can keep the frequency unchanged in a small range. However, if an isolator with linear stiffness is used, the frequency value of the new multi-degree of freedom system would not be close to the desired or designed value. By analysis of the different loading conditions for Chengdu metro, the nonlinear isolator is suitable for the non-overload condition of the vehicle. Finally, the wheel load drop test proves the good consistency between experimental results and theoretical prediction.