Fatigue Crack Initiation and Life Prediction of Rail Weldment Under the Effect of Vertical and Lateral Load Conditions in Indian Railways

Abstract

Being a mechanical structure, rail beam is one of common but prominent element of railway track arrangement, and rail–wheel contact mechanism plays a significant role for the reliability of the whole railway system. Indian Railway uses long welded rail (LWR) as a major portion in its track network, so it has become an inseparable and important segment of Indian Railways. The stress pattern may be of different in the weldment due to welding operation as well as the weld may experience a remarkable change in its dimensional parameter because of the action of forces acting in vertical and lateral direction under dynamic conditions. Stress analysis is the most important study to find the permissible fracture limit which may occur in fatigue to provide the suitable time for replacing or repairing rail and its weldment. Indian Railways regularly performs the maintenance task like fracture repair, replacement and joining, etc., so for above purposes, a study on high cycle fatigue under multiaxial loadings and the weld life prediction for rail has been performed in this article. A 3D EPFEM of rail–wheel–weld having contact between them has been made by using ANSYS academic software and for achieving both efficiency and accuracy under high-end computational work software-based fine meshing is applied at wheel–rail contact. Also this study has used a model for crack initiation based on multiaxial fatigue for performing stress analysis to find fatigue damage in rail weldment numerically. Investigation is made for the vertical/lateral loads effect, hardness of material, and attributes associated with fatigue in material at wheel–rail/weld contact position by utilizing stress history under unit loading cycle for initiation of crack and fatigue life and its damage model. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.