A Survey of Rail Vehicle Track Simulations and Flexible Multibody Dynamics

The important development in rolling contact theory withthe recent advances made in the field of flexible multibody dynamics canserve as the foundation for developing new analysis and designcomputational methods for railroad vehicle/track systems. Multibody computational methods can be used tosimulate the dynamic effects due to the structural flexibility of thevehicle components and the track, multiple coupled railway carsnegotiating variable track geometry, derailments resulting from gagewidening, three-dimensional wheel/rail contact, vehicle trackinteraction, and vehicle dynamics under high operating speeds. Asdiscussed in this review paper, based on the new development in rollingcontact theory, one can predict the contact forces between the wheel andthe rail when realistic kinematic and dynamic descriptions are providedat the contact points. Basic quantities such as the longitudinal,lateral and spin creepages are essential for the accurate prediction ofthe contact forces. Nonetheless, in many investigations, linearized orpartially linearized kinematic expressions are used to define thecreepages. Using new multibody algorithms which allowfor the analysis of nonlinear models, the linearization schemescurrently employed in railroad vehicle/track research can be evaluated.Other related issues considered in thissurvey article include wheel/track interaction models, safetyconsideration, experimental verification of simulation results, andapplications which can significantly benefit from adopting the moregeneral computational flexible multibody techniques. As oneof the main objectives of this survey article is to shed more light onthe limitations of some of the current simulation tools used by railroadindustry and at the same time demonstrate the benefits of adoptingcomputational flexible multibody methodologies in railroad vehicle/tracksimulations, some future research areas are identified in the Summaryand Conclusions section.