Prediction of the geometry change of switch frog

Abstract

The switch frog is one of the most costly infrastructure rail components and yet exhibits short service life. Due to higher wheel-rail contact pressures as the wheel travels in both directions of the frogs, the switch frog deteriorates which results in its shorter service life in comparison to other components. In the aspect of deterioration and geometry, the optimal geometry of the switch frog should be determined to achieve longer service life. This study aims to examine the geometry changes of switch frogs with respect to the influence of the vertical wear area, which is caused by the wheel-rail contact pressure. To analyze and predict the geometry changes, a mathematical model is created in relation to the vertical wear area of the cross-sections along the longitudinal axis. The analysis is based on the measurement data of 13 rigid switch frogs. The results show varying degrees of deviations between the measurement data and the model depending on the considered cross-section. However, these deviations can be narrowed by further calibrating the model with the measured data as a benchmark of accuracy. In future studies, the model needs to be improved to correspond with any initial geometry and be able to extend for the trailing move direction.