A method for the prediction of head checking initiation location and orientation under operational loading conditions

Head checking (HC) as a surface-initiated rolling contact fatigue damage in rails has been a problem for many railways. Countermeasures such as optimal design of wheel and rail profiles, optimal design of the vehicle-track interaction system, HC-resistant rail materials, etc. are being developed. Such development requires a better understanding of the relationship between the operational loading conditions of the rails and the initiation of HC. This article presents an effective non-Hertzian method for evaluating the stress state on the rail and wheel surfaces under operational conditions, so that HC initiation location and orientation can be directly related to the stress. It is shown that the HC initiation location and orientation derived from the computed stress state are in agreement with those observed in the field.