Finite Element Methodology for Flexible Track Models in Railway Dynamics Applications

The dynamic analysis of railway vehicles involves the independent construction of models representing vehicle, track and wheel-rail contact. In this work, a multibody formulation with Cartesian coordinates is used to describe the kinematics of the rigid bodies and joints in the vehicle model. In order to create detailed three-dimensional track finite element models, a methodology that includes the flexibility of rails and substructure is proposed. Finite element methodology is used to model the rails as beams supported in a discrete manner by spring-damper systems that represent the flexibility of pads, sleepers, ballast and substructure. The inclusion of flexible track models is very important to study the dynamic behaviour of railway vehicles in realistic operation scenarios. The proposed wheel-rail contact formulation outputs, the contact points location in real time during the dynamic analysis, for the most general three-dimensional motion of the wheelsets with respect to the track. The proposed methodology to build flexible track models is validated by comparing the results obtained with this new approach with the ones obtained using ANSYS. The methodology is demonstrated by studying the dynamic behaviour of the Alfa Pendular railway vehicle.