Detailed Models for Dynamic Analysis of Railway Vehicles

The realism of the multibody models of railway vehicles is greatly influenced by the modelling assumptions. In particular, the representation of mechanical joints with clearance by spring elements or by dedicated modelling is a major issue addressed in this paper. In order to determine the importance of modelling, two different multibody models of the Light Rail Vehicle 2000 (LRV) are constructed and analysed. In the primary suspension, there are guides and the bogie-carbody connection uses a kingpin. Two different proposals are made to model these mechanical elements: to use linear force elements; or to use joints with clearance, recently proposed in multibody dynamics. Thus, the two multibody models are developed and both are simulated on two different railway tracks. The first track is a simple tangent plus curve segment. The second track is a real railway track which is part of a railway network. In this paper, not only the dynamic performance of the models is analysed, but also their compatibility with the tracks. In the curved track, the non-compensated acceleration measured on the carbody is analysed. In the real track, the characteristic values which are computed as described in the Simple Method of the international standards UIC 518 and EN 14363 are the object of the study. These values define the acceptance of the dynamic behaviour of railway vehicles by regularity entities. The compatibility of the multibody models with the track is not only by processing all relevant dynamic response data but also by using an animation tool, in which the relative motion of the wheelsets on the tracks is visualised. Events of wheel climbing and contact losses are detected using this computer graphic tool.