A mathematical model for simulating the longitudinal-vertical motion of railroad cars in impact situations is described in this document. Development and validation of the model was part of a study concerned with the phenomenon of coupler bypass resulting from impact or squeeze. The model represents each car as an idealized dynamic system, consisting of springs, masses and dampers and possessing up to 6 degrees of freedom (12 state variables) per car. The degrees of freedom correspond to the longitudinal, vertical and pitching motion of car bodies, lading motion, and truck motion (front and rear separately). The model is capable of representing friction draft gears as well as hydraulic cushioning devices. The model accounts for friction between truck side frame and bolster, possible separation of the truck center plate from the truck bolster and coupler disengagement. A limitation of the model is that, in the absence of more accurate information, the force-deflection relationship of car underframes is represented by linear springs. However, it can be readily modified to represent non-linear force-deflection relationships once those relationships are quantified.

  • Record URL:
  • Corporate Authors:

    Washington University, St Louis

    School of Engineering and Applied Science
    St Louis, MO  United States  63130

    Federal Railroad Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Yin, S K
  • Publication Date: 1980-4

Media Info

  • Pagination: 69 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00314067
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FRA/ORD-76/278 Tech Rpt.
  • Contract Numbers: DOT-OS-40106
  • Files: NTIS, TRIS, USDOT
  • Created Date: Aug 5 1980 12:00AM