WEAR-TYPE RAIL CORRUGATION PREDICTION: PASSAGE TIME DELAY EFFECTS

The growth behaviour of the vibrational wear phenomenon known as rail corrugation is investigated using analytical and numerical models. A feedback model for wear-type rail corrugation that includes a wheel pass time delay is investigated with an aim to determine what effects the time between successive wheel passages has on the growth of the amplitude of corrugations. The feedback model is simplified to encapsulate the most critical interactions occurring between the wheel/rail structural dynamics, rolling contact mechanics and rail wear. A stability analysis on the system yields the growth of weartype rail corrugations over multiple wheelset passages as a function of the passage time delay magnitude. Based on these results, numerical and analytical investigations are performed to identify conditions under which the passage time delay has a significant effect on the growth of corrugations. Nomenclature C [ Sensitivity of creep to contact force variations i r G Modal growth rate parameter 0 k Wear coefficient c k Contact stiffness b K Sensitivity of the steady state response of wheel/rail relative displacement to a step change in input longitudinal profile i c K Modal sensitivity of the steady state response of wheel/rail relative displacement to a step change in input longitudinal profile ‡ Laplace transform operator i m , i Z , i