Numerical study of the transition characteristics and related degradation at the flange bearing frog

Abstract

Wheel-load transition process of the flange bearing frog is so complex: the wheel-load transits from the tread to the flange, and then back to the tread. To improve the understanding of the frictional rolling contact behavior and the related degradation at the flange bearing frog in the divergent direction, an explicit 3D finite element model simulating the interaction between the frog and the wheel is established; the precise distribution and evolution of contact pressure, micro-slip as well as the shear stress along the longitudinal axle of the frog can be derived through the transient rolling contact calculations. The results show that the contact patch located at the flange will be shifted forward compared to the contact patch at the tread due to the structural irregularities, and the flange bearing mode can significantly increase the value of stress; both the plastic strain and the frictional work reach a maximum at the bearing flangeway. Therefore, the bearing flangeway is susceptible to severe damage. The explicit finite element method is able to effectively analyze the degradation mechanism of the flange bearing frog.