Probabilistic Assessment of the Crosswind Stability of Railway Vehicles

The crosswind stability against overturning is a major design criterion for high speed railway vehicles. Due to the increasing interoperability in Europe it has also become an important international task. In recent years efforts have been made to derive an uniform rule in certifying railway vehicles. In this case especially probabilistic methods have been proposed which are common design criteria for wind turbines. A sophisticated method to compute the reliability of railway vehicles under strong crosswind is presented. In consideration of the given stochastic wind excitation the response of a simplified train model and the corresponding probability of failure have been computed. The major failure criterion to determine the reliability is the lowest wheel-rail contact force of the railway vehicle. In the product development process it is a common goal to calculate the virtual prototype as realistic as possible but it is also essential to minimize the computational efforts. For a probabilistic analysis this means to take only the most significant stochastic variables into account and to neglect the unimportant ones. To isolate the major variables a sensitivity analysis with respect to the stochastic excitation variables has been done. But not only the knowledge about the influence of the excitation variables is crucial, also the impact of the design parameters of the railway vehicle on the crosswind stability is important to know. To get a deeper insight into the system also a sensitivity analysis with respect to the deterministic design parameters has been done.