Technical Reports

Comparative Analysis of Dynamics of Freight and Passenger Rail Vehicles

  • 01
  • Nov
  • 1976
AUTHOR: Donald R. Ahlbeck, George R. Doyle
OFFICE: RPD
REPORT NUMBER: FRA/ORD-77/04
SUBJECT: Track/Train Interactions
KEYWORDS: Rail Vehicle Dynamics, Computer Modeling, Random Track Geometry, Ride Comfort
ABSTRACT: During the course of this contract, analytical studies have been conducted on several different rail vehicles typical of North American railroad operations mathematical models, and computer codes for the mechanization of these models have been generated under this contract to provide a predictive methodology for determining vehicle/track dynamic interaction under a range of conditions. These models have been validated through comparison of results with test data from several of the rail vehicles. Results of a comparative analysis of nine different rail vehicles were presented in a Final Report (FRA-ORD&D-74-39) dated March 1974. In subsequent contract modifications, the analytical techniques were used to provide support to the Metroliner Ride Improvement Program (DOT-FR-20049). Both the vehicle ride comfort and truck hunting stability were investigated by means of computer simulation. Parameter variation studies were used to determine optimum suspension values for both ride comfort and hunting stability. This report provides a summary of work conducted under the original contract and five subsequent modifications. Recent modifications to the mathematical models to improve simulation accuracy are discussed. In addition, improvements in the representation of track geometry in power spectral density format based on recent measurements are discussed.

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