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

When train passes through the rail joint at the heel of tongue rail of railroad switch, impact vibration is caused due to the step difference of the joint. This impact vibration is transmitted 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 leading to switching failure. Also, the wear of bearing of the special layout switch is more serious than that of the normal railroad switch because the special layout switch is more complex than the normal railroad switch. In order to clarify the mechanism of the wear, we measured the acceleration and axial force of the front rod of the special layout railroad switch in track open for traffic. Then, we have developed the finite element model of the special switch and validated the model by comparing with measured results. On the other hand, we calculated the coefficient of wear amount of bearing from wear test. Combining with the results of finite element analysis and the coefficient of wear amount, we predicted the wear amount of the front rod in the track. The wear amount of bearing of the special railroad switch is 10 to 20 times more than that of the normal railroad switch (Kondo et al., 2015). This is because the material of bearing of special switch is easier to wear than that of normal switch. Furthermore, the result is attributed to the structure of bearing of special switch. The axial constraint of bearing of special switch is weaker than that of normal switch, and so the bearing of special switch is easy to slide.