Technical Reports

Analyses of Track Shift Under High-Speed Vehicle-Track Interaction

  • 01
  • Jun
  • 1997
AUTHOR: G. Samavedam, F. Blader, D. Wormley, M. Snyder, J. Gomes, A. Kish
SUBJECT: Evaluation
KEYWORDS: Track Lateral Shift, Net Axle Force Ratio, Vehicle-Track Interaction, Track Residual Deflection, OMNISM
ABSTRACT: This report describes analysis tools to predict shift under high-speed vehicle-track interaction. The analysis approach is based on two fundamental models developed (as part of this research); the first model computes the track lateral residual deflections under vehicle passage, whereas the second determines the lateral dynamic loads generated as the vehicle negotiates misaligned tangent or curved tracks. The track residual deflection model takes the loads from the vehicle dynamic model as inputs and is based on a quasi-static beam theory and an appropriate tri-linear constitutive representation for the tie-ballast lateral resistance under the wheel vertical loads. The vehicle dynamic model is based on a simulation which maintains a wheel-rail rolling contact connection with a complaint track representation. computer codes (OMNISIM) for track residual deflection and for vehicle multi-body simulation with complaint track element have been developed to facilitate parametric study. OMNISIM, which has been developed through extensive modifications of previous programs (which do not permit a complaint track element) is shown to have several advantages including accuracy in the evaluation of loads and wheel climb predictions.