Analysis of Coherence between Track Random Irregularity and Vehicle Dynamic Response

The track irregularity function measured by the railway inspection car and that transferred from the track irregularity power spectral density(PSD) are used as the exciting functions of the vehicle-track coupled dynamic simulating model to calculate the forces between wheel and rail and the dynamic response of the vehicle.The low exciting track irregularity PSD of China's high-speed railway,the sixth grade track irregularity PSD of U.S. railway and the track irregularity PSD coming from China's certain trunk railway are used as an exciting function to calculate the wheel/rail forces and dynamic response of vehicle under different train speeds.The simulating results are also compared with each other.The coherence calculation is made for analyzing the relationship between vehicle response and the track irregularity,and the most detrimental random irregularity wavelengths that affects the wheel/rail forces and vehicle response is confirmed in the paper.