Railhead corrugation growth explained by dynamic interaction between track and bogie wheelsets

Short-wave railhead corrugation growth on tangent tracks due to wear from driven locomotive wheels is investigated. A track model with a given initial random railhead irregularity is used. The track parameters and the railhead irregularities are estimated from measurements performed on a newly built track. The corrugation calculations are based on rolling contact mechanics; a semi-empirical relationship between creep, friction force and normal contact force is employed. Only longitudinal creep and creep forces are taken into account. The vertical contact forces between the moving wheels and the rail are calculated using a time-stepping method, allowing for a non-linear Hertzian wheel/rail contact stiffness. Numerical examples are given. It is found that the two wheelsets of a travelling bogie interact and that both of them should be considered in the same calculation. The bogie wheelbase turns out to be an important parameter.