摘要:
This thesis presents the theories and numerical simulations in regard to the behaviour of a single-axle railway wheelset commonly used in cargo rail cars, Specifically, creep forces, dynamic models, real wheel~rail profiles, and multiple point contact will be investigated. One of the most important aspects of wheel~rail interactions is the creep force. Creep force results from the relative motion between the wheel and rail. The extent of such relative motion is measured by creepage, which is defined as the difference between ideal, or pure rolling, where the velocities of the wheel and rail relative to one another are equal, and the deviation of such. Creep force is an important design factor in relation to rail transport safety and efficiency as well as wheel and rail longevity. Calculation of the dynamic creep forces will be completed with a nine~step process and benchmarked against Polach and Kalker. The Polach benchmarking tests three sets of creepage combinations proposed by Polach. In this test, a total of fifteen cases are tested. The relative accuracy and computational efficiency amongst the theories is determined. The creep forces are then plotted with respect to specific track cases and compared with multiple theories including Kalker's FASTSIM results. Three dynamic models will then be presented, and compared. These models will be tested under specific track conditions from the Manchester Benchmarks' Track Case 2 (TC2). These models will be compared in the response, the time to calculate and the flexibility of the model to withstand parameter deviations. Real wheel and rail profiles will then be introduced to replace the coned wheels and knife-edge rail assumption in one final model. This model makes neither small angle assumptions nor normal force assumptions. Contact conditions will include one-point contact, at either the tread or the flange, as well as two-point tread-flange contact. This model will be tested again with TC2. Hunting, a side-to-side movement