THE RIGID BODY DYNAMICS OF ROAD VEHICLE TRAINS. PROCEEDINGS ENTITLED "THE DYNAMICS OF VEHICLES ON ROADS AND ON RAILWAY TRACKS"
Theory regarding linearized equations governing the vertical and lateral motion of road vehicle trains is outlined. A road train is defined as a tractor unit plus an arbitrary number of trailers. Equations for evaluating the rigid body dynamics of road trains are solved by determining system eigen values and vectors. In practice, road trains are usually a tractor plus semitrailer (plus full trailers) or a truck (plus full trailers); a family of trains of both types is defined using, where possible, the same elements and then calculating behavior. Vertical motion results indicate that tractor plus semitrailer trains have poorer ride characteristics. More extensive lateral studies cover speed, "dolly" geometry, and loading variations. Poorly-damped full trailer modes of motion are at their worst under lower loading conditions. The only lateral instability that was observed involves oversteer of the truck with a rearward center of gravity location. The implication is that truck trains have more favorable ride characteristics, with lower natural frequencies and lower amplitudes for the truck in higher frequency modes, especially in pitching motion. Lateral motions generally follow the usual automobile pattern, with oscillatory motions dominant. Stability is reduced with increasing speed, and additional modes resulting from adding more trailers reduce overall system stability.
- Also published in HS-026 982U, "The Dynamics of Vehicles on Roads and on Railway Tracks. Proceedings of International Union of Theoretical and Applied Mechanics Symposium, Delft, The Netherlands, 1975 August 18-22," Amsterdam, 1976 p 131-51.
International Union of Theoretical and Applied MechanicsChalmers University of Technology, Sweden
S-412 96 Gothenburg, Sweden
- HALES, F D
- Publication Date: 1976
- Features: References;
- Pagination: 21 p.
- TRT Terms: Equations; Loads; Motion; Motor vehicles; Ride quality; Speed; Stability (Mechanics); Tractor trailer combinations; Traffic speed; Vehicle dynamics
- Subject Areas: Motor Carriers; Safety and Human Factors;
- Accession Number: 00394099
- Record Type: Publication
- Source Agency: National Highway Traffic Safety Administration
- Report/Paper Numbers: HS-026 989U
- Files: HSL, USDOT
- Created Date: May 31 1985 12:00AM