The report presents the development of general analytical models for use in exploring the nature of freight car hunting and for finding means of controlling the hunting behavior. These models result from one aspect of the Freight Car Dynamics research project conducted by Clemson and Arizona State Universities in cooperation with the Association of American Railroads. First, a model of a wheelset with lateral, yaw, and axle torsional degrees of freedom is developed. Secondly, two such wheelsets are included in a general model of a 9 degree of freedom truck that has lateral, yaw, and warp degrees of freedom in addition to relative lateral and yaw motions of the wheelsets with respect to the truck frame. By suitable choices of primary suspension elements, this general model may be specialized to become (1) a roller-bearing freight truck, (2) a plain-bearing freight truck, (3) a roller-bearing truck with primary suspension elements, (4) a passenger truck, (5) a generic model of a freight truck with interconnected wheelsets, or (6) a rigid truck. Finally, two such truck models are combined with a car body that has lateral, yaw, and roll rigid body degrees of freedom plus two degrees of freedom that serve to approximate the first lateral bending and torsional modes. For all three models, the effects of design parameters on the critical speed for hunting are examined.

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 229 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00167302
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FRA/ORD-77/36 Intrm Rpt.
  • Contract Numbers: DOT-OS-40018
  • Files: NTIS, TRIS, USDOT
  • Created Date: Nov 23 1978 12:00AM