Dynamics simulation of a high-speed railway car operating in low-temperature environments with stochastic parameters

The dynamic performance of a high-speed railway vehicle operating in low-temperature environments was studied through simulations using a stochastic, parameter-based, dynamic model. This model considered the random distribution of the design and operational parameters due to variations in operating conditions and manufacturing errors, as well as the maintenance procedure. The effects of the ambient temperature on the properties of the vehicle suspensions, such as the rubber-made elements, hydraulic dampers and air springs, were determined through laboratory tests. The results suggest that the low-temperature operating conditions substantially increase the stiffness and damping properties of the rubber components and hydraulic dampers, especially when the temperature is less than −20°C. In extremely low-temperature operating conditions, the vehicle with a relatively small equivalent conicity could be subjected to car body hunting, thereby deteriorating the ride comfort. Therefore, a minimum wheel equivalent conicity of greater than 0.1 is suggested. By considering the scenarios of snow build-up on the bogie, the results further show that the snow could limit the motion of the suspension and significantly affect the dynamic performance of the vehicle. However, the effect of the added mass on the bogie is considered to be negligible.