A 14 DEGREES OF FREEDOM MATHEMATICAL MODEL TO PREDICT CAR HANDLING BEHAVIOUR ON SMOOTH AND ON BUMPY ROADS. PROCEEDINGS ENTITLED "THE DYNAMICS OF VEHICLES ON ROADS AND ON RAILWAY TRACKS"

A car mathematical model has been formulated which treats the vehicle as an assembly of rigid masses connected together and to the road by flexible elements (suspensions and tires). The model consists of 14 differential equations, 10 of which have been derived from Lagrange's equilibrium equations. Inertial terms are deduced from the car's kinetic energy and its rotating components in order to reflect gyro and equivalent mass effects. Since vertical inertia of wheels and tire deflection are considered, the simulation of car behavior on bumpy roads becomes possible. Further, computations for roll, pitch, and bounce include the contribution of tire vertical deflections. Care has been taken to obtain accurate mathematical expressions for car and tire experimental characteristics because the reliability of results depends largely upon the quality of input data. Any useless assumption of linearity has been avoided. Of two available computer programs, one includes a procedure that enables the simulation of transient maneuvers along a given trajectory. The second has been set up to investigate steady-state car behavior. Examples depict the model's capability in predicting car handling behavior on both smooth and bumpy roads. Supplementary equations and notations are appended.

  • Supplemental Notes:
    • 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, Netherlands, 1975 August 18-22," Amsterdam, 1976 p 86-109.
  • Corporate Authors:

    International Union of Theoretical and Applied Mechanics

    Chalmers University of Technology, Sweden
    S-412 96 Gothenburg,   Sweden 
  • Authors:
    • Rinonapoli, L
    • Bergomi, R
  • Publication Date: 1976

Media Info

  • Features: References;
  • Pagination: 24 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00394095
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: HS-026 986U
  • Files: HSL, USDOT
  • Created Date: May 31 1985 12:00AM