Optimisation of the dynamic properties of ladder track to minimise the chance of rail corrugation

The ladder track used by the Beijing subway which can be subjected to rail corrugation is considered in this paper. Dynamic models of the vehicle and the ladder track are developed to analyse the track vibration behaviour. Using these models the effect of the most significant ladder track parameters on track vibrations are analysed in the frequency and time domains. Using experimental and numerical results the vibration frequency of the rail that is responsible for rail corrugation is determined. Based on the results of the parametric study, an optimisation of the mechanical properties of the ladder track to reduce or eliminate the track vibrations at the corrugation frequency and ultimately to reduce the chance of rail corrugation is performed using a genetic algorithm-based approach. The results of the optimisation are presented and discussed.