Simulation of Fatigue Failure of Rail Joint Bolts by FEA
It is well known that the fatigue failure of bolts can affect the performance of rail joint and the safety of train running. In this work, the influence of the bolt torque and radius of rounded root of rail bolt on the fatigue strength of the rail bolt are studied by Finite Element Contact Analysis method. And the influence effects of the wheel impact and temperature force of the rail caused by temperature changed on bolt failure are studied. The results indicate that properly torque and increasing the radius of rounded root rail bolt can reduce the stress concentration at the root of rail bolt and this will improves the fatigue strength and the working life of the rail bolt and rail joint. The repeated temperature force of the rail and wheel impact force are playing an important role in the influencing factors on fatigue failure of the rail joint bolts. Due to this, the two bolts near the rail joints will to be fatigue failure almost earlier than others. That is one of the reasons why the bolts should be preloaded or replaced regularly.
Qingkai Han, Kazuhiko Takahashi, Chang-Hyun Oh and Zhong Luo
X. P. Li et al., "Simulation of Fatigue Failure of Rail Joint Bolts by FEA", Advanced Engineering Forum, Vols. 2-3, pp. 1035-1040, 2012