LAUSR

Abstract The character of wheel–rail contact influences vehicle dynamics performance. Using vehicle–track dynamics theory, we establish a railway vehicle–track dynamics model with a 30t axle load. We analyse the sensitivity of different track and vehicle factors to the wheel–rail force using sensitivity analysis, calculate the sensitivity factors of each parameter and determine the sensitivity parameters. We then perform Monte Carlo simulations to produce random samples of sensitive parameters and analyse the characteristic distributions of wheel–rail contact under random track and vehicle parameters. The results show that: train speed, integral vertical track stiffness, integral lateral track stiffness and the vertical stiffness of each vehicle’s bolster spring are all parameters sensitive to the wheel–rail contact character. Under the condition of random parameters and track irregularity excitation, a random wheel–rail force follows a Gaussian distribution, the maximum wheel–rail force obeys an extreme type I distribution, and the wheel–rail contact position distribution is uniform with two main distribution areas.