Feasibility of Track Energy Metric

Identifying track locations with rapid degradation potential and derailment risks due to structural failure is important for the railroad industry. Among the tools used to identify degradation are Track Quality Indexes (TQIs), a track geometry-based metric to characterize overall track quality. However, TQIs generally do not reflect the effect of short wavelength events, such as poor rail joints, or considerations required for long wavelengths track features such as curves. Additionally, TQIs do not reflect vehicle-track interaction (VTI) and the potential damage to rolling stock components. Therefore, a metric that identifies track areas of concern by appropriately capturing the effects of a wide range of defect wavelengths and potential VTI forces would benefit the railroad industry. From June 2016 to June 2017, the Federal Railroad Administration (FRA) sponsored a study, executed by ENSCO, to develop a track energy metric (TEM). The method is based on the hypothesis that track locations with higher energy transfer rates between vehicle and track correspond to locations with higher track degradation rates. A portion of these locations could also translate into higher rolling stock component degradation rates. The formulation of the proposed metric is intended to capture information from a broad range of track wavelengths as well as VTI. Simplified dynamic models were used to develop a TEM formulation in the vertical direction only using acceleration, mass, and the conservation of energy law. Simulation results showed good agreement between theoretical TEM calculations and computer simulation derived values for contact force and energy transfer into track. The study indicated that the TEM formulation could effectively reflect mechanical energy transferred into a track in the vertical direction and hence identify locations with potential high track degradation rates. However, this study would have to be further expanded to generalize the TEM formulation to account for and assess its accuracy in the lateral direction as well as the effects of energy dissipation.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures;
  • Pagination: 4p
  • Serial:
    • Research Results
    • Issue Number: RR 18-07
    • Publisher: Federal Railroad Administration
  • Publication flags:

    Open Access (libre)

Subject/Index Terms

Filing Info

  • Accession Number: 01667887
  • Record Type: Publication
  • Files: TRIS, ATRI, USDOT
  • Created Date: Apr 11 2018 2:22PM