Simulation of track-locomotive interactions in the longitudinal direction

Interest has been expressed from industry regarding the investigation of longitudinal interactions of tracks and locomotives. The majority of railway track dynamics models focus on vertical and lateral directions; railway track longitudinal force models are rarely published. This paper developed a three dimensional railway track model which considers four structure layers: rails, sleepers, ballast and subballast. The rails are modelled using the Finite Element Method (FEM) and each node has six Degrees of Freedom (DoFs). Sleepers are modelled as rigid bodies and each also has six DoFs. Ballast and subballast are modelled as blocks and each has three translational DoFs. Frictional behaviour is considered in the longitudinal direction of the fastening models as well as in the longitudinal and lateral directions of the sleeper-ballast force connections. Locomotive-track interaction simulations are conducted using a parallel cosimulation technique to combine the track model to a locomotive model developed in GENSYS.