Loop track: an infinite long track model

ABSTRACT This paper developed a track model called the ‘Loop Track’ that had a new function to simulate infinite long tracks without heavy data movement. The model was three-dimensional and considers rails, sleepers, ballast, subballast, and subgrade. Rails were modelled by using the Finite Element Method whilst all other components were modelled as equivalent rigid bodies connected by flexible force elements. The loop or infinite feature of the model was achieved by adding an extra boundary section to link the last node set to the first node set of the original track model. Case studies were conducted to simulate infinite long tracks and variable track conditions, as well as to determine the minimum track length required for different simulations. Results show that the recommended minimum track lengths for the simulated cases were 76 sleepers for vertical track dynamics and 301 sleepers for longitudinal track dynamics.