Fatigue design of continuous thermite-welded rail

초록

Since continuous rails are made by welding a certain length of rail, there is a possibility that fatigue cracks may occur due to train passage. Since thermally welded long rails are constructed in the field, there is a higher probability of welding defects compared to other welding methods. Therefore, the fatigue life of continuous rails can be determined by the fatigue life of thermite-welded connection. In this study, the fatigue life of thermite-welded continuous rails presented in existing studies was verified. The fatigue strength of thermitewelded continuous rails was evaluated based on linear elastic fracture mechanics by analyzing the existing experi- mental results. The fatigue life and crack shape at failure were used to obtain the initial crack size for crack growth analysis. The stress intensity factor range threshold utilized to obtain the fatigue limit is determined by the stress ratio. Changes in residual stress due to seasonal temperature changes cause changes in the stress ratio acting on the rail, and therefore changes in the fatigue limit occur depending on the season. Considering these features, a fatigue design method for ther- mite-welded continuous rail is proposed. © 2024 The Author(s).