Vehicle/track dynamic models for wheel/rail forces and track response

Two types of vertical vehicle/track dynamic model are described in the paper. One is a coupled moving vehicle/track finite element model and the other is a lumped parameter model. The finite element model allows a vehicle to move along the track and is capable of considering variable track parameters such as track stiffness and tie support along the track, as well as the existence of rail joints. The lumped parameter model is a simplified model. The method for determining equivalent model parameters is discussed. The major output of these two models are wheel/rail dynamic forces and dynamic track responses under excitation at relatively high frequencies. In addition, the development of a track model to be installed into the AAR's NUCARS vehicle/truck interaction model is discussed briefly.