Finite element modelling for the wear prediction of front rod of railroad switch due to the impact vibration caused by train passage

Abstract

When train passes through the railroad joint at the heel of tongue rail of railroad switch, impact vibration is induced due to the step difference of the joint. This impact vibration transfers to the front rod, which is the attachment device located on the toe of tongue rail and connected with position checker device, induces the wear of bearing and resulting switching failure. In order to clarify the mechanism of the wear, we have developed the finite element model of the railroad switch for the vibration analysis. The model is validated by the acceleration and axial force of the front rod measured in track open for traffic. Our model enables us to predict the wear amount from the contact pressure and sliding velocity of the bearing part. Combining with wear test and finite element model, we predicted the wear amount of the front rod in the track and found that the time to reach the limit of wear is over 80 years. Therefore, the present replacement period is thought to be extensively conservative. Our final goal is to propose the appropriate maintenance schedule for any other type of railroad switch under various working conditions.