Study On The Vibration Transmission Characteristics Of Spriral Steel Spring And Isolation Measures

With the rapid development of railway transport in recent years, the speed of the vehicle is higher and higher. The impact between wheel and rail when the vehicle run on the track is becoming increasingly violent, at the same time, the excitation frequency is also increasing. These harmful vibrations seriously affect the safety and ride comfort of the train. In order to reduce the harmful vibration of the vehicle, the installation of the spring vibration damping device is used to reduce the impulse and vibration. Spiral steel springs are commonly used to relax the vibration as the spring device, but the spiral steel springs will transmit high frequency vibration. Rubber, as a kind of material with good damping and vibration absorption, is often used as a vibration damping device on the vehicle, therefore the rubber pad is used in series with the spiral steel spring. It is very important to study the vibration transfer characteristics of the spiral steel spring, the dynamic performance of the rubber pad and the combined system of the spiral steel spring in series with the rubber pad, which has a certain help to solve the practical problems encountered in the operation of the vehicle as well as the parameters design of the vehicle.Based on Ansys finite element software, this paper have respectively analyzed the steel spring, the rubber pad, the combined system of the spiral steel spring in series with the rubber pad using the finite element method, and done a comparative study between the empirical formula and the test results. This paper has done the following work:(1) The finite element model of the spiral steel spring is established, and the static and dynamic characteristics of spiral steel spring are studied. It is found that the static stiffness of the steel spring increases with the increase of the load, the frequency characteristic of the steel spring is existed, and the quality and the self-vibration behavior of the steel spring have great influence on the frequency characteristic of the steel spring. When the excitation frequency is at a very small level, the dynamic stiffness and static stiffness of the steel spring differ very little; when the excitation frequency increases gradually before the resonant frequency, the stiffness decreases with the increase of frequency. When the excitation frequency is close to the anti-resonant frequency, the dynamic stiffness will become very large, but in general, the dynamic stiffness of the steel spring increases with the increase of the frequency, and the experimental results are used to verify the results.(2) Based on the hyperelastic Mooney’-Rivlin constitutive model and viscoelastic model Prony series, the viscoelastic finite element model of the rubber pad is established, and the influence of the rubber hardness on the vertical stiffness of the rubber pad is analyzed, and the dynamic stiffness and damping characteristics under different frequency is also analyzed. It is found that the dynamic stiffness of the rubber pad increases with the increase of the excitation frequency, and the dynamic stiffness increases very fast at low frequency, and the increase is slow at high frequency. The damping of the rubber pad decreases with the increase of the excitation frequency, and the damping decreases very quickly at low frequency. In the case of low amplitude, the dynamic stiffness and damping of the rubber pad hardly changes with the change of the excitation amplitude.(3) The finite element model of the combined system of the spiral steel spring in series with the rubber pad is established, and the characteristics of the vertical stiffness of the combined system are analyzed. And the finite element model of the combined system of the spiral steel spring in series with the rubber pad and the finite element model of the steel spring are compared and analyzed, and it is found that vertical stiffness of the combined system is smaller than that of the steel spring, and combined system can reduce stress level of the stiffness of the steel spring.(4)Based on the SIMPACK multi-body dynamic software, a simple model of the car body and the vibration damping element is established, and the vibration transfer characteristics of the spiral steel spring and the combined system of the spiral steel spring in series with the rubber pad are analyzed under different frequency. It is proved that the combined system of the spiral steel spring in series with the rubber pad is indeed able to attenuate the high frequency vibration transmitted by the spiral steel spring.