Elastic force model for wheel/rail contact in multibody railroad vehicle systems

Many investigations on rail vehicle dynamics are concerned with the analysis of the wheel/rail interaction at high speeds. Achieving the minimum design criteria for the stability of high-speed rail vehicles, which can operate at speeds above 200 km/h, requires special considerations. The vehicle stability is significantly influenced by the contact between the wheel and the rail and the dynamic forces resulting from their interaction. This thesis presents and discusses computational methods that can be used for the non-linear dynamic analysis of a multibody wheel/rail contact. The objective of this work is to contribute to the development of several accurate, efficient, and useful computational tools that can be used in the design and dynamic analysis of the railroad vehicle systems. An elastic force model that accounts for the wheel/rail contact problem had been developed. In this model, the wheel can have multiple contacts. The wheel/rail normal contact force is evaluated by using Hertz's contact theory.; As the lateral stability is one of the most important problems in railroad vehicles dynamics, a complete analysis of lateral stability for railroad vehicle using the model presented in this thesis is investigated. It was shown that the constraint and the elastic approaches are in a good agreement with the linear approach.; A detailed vehicle model is developed and investigated using a general multibody code. The important problem of the curving behavior in the railroad vehicle dynamics is examined using this detailed vehicle model.