Parametric study of wheel flats effects on dynamic forces and derailment coefficient in turnouts

Evaluating and predicting the possibility of derailment at turnouts is important in operation and maintenance. In addition, wheel flat defect is one of the sources of infrastructure damage due to the occurrence of severe impact forces. In this paper, the dynamic and safety studies of a freight train with a defective wheel when passing through turnouts are investigated. After modelling and validation, the evaluation of the wheel-rail dynamic forces and derailment coefficient at turnout has been done using the multibody dynamic universal mechanism (UM), and the effect of the wheel flat depth on these items has been evaluated. The results indicate that the depth of the wheel flat, as well as the train speed, strongly affect the dynamic forces and derailment coefficient at the turnout. Excessive dynamic forces, with the creation and growth of wheel and rail defects, are the cause of derailment, accidents, and destruction, and must be continuously monitored.