INFLUENCE OF THE SMALL VERTICAL MOVEMENTS OF VEHICLES AND OF THE EVENNESS OF THE PAVEMENT ON COMFORT AND SAFETY

INCIDENCE SUR LE CONFORT ET LA SECURITE DES PETITS MOUVEMENTS VERTICAUX DU VEHICULE ET DE L'UNI DE LA CHAUSSEE

The article presents the results of a thesis on the effect of pavement evenness on the vehicle vertical movements. Details are given of the mathematical model used for vehicle simulation, the tests carried out to calculate the model's parameters and the results obtained (theoretical results with the model and practical results on experimental or real roads). The main characteristics of the model are: two-degree of freedom non-linear model; variable suspension damping depending on the direction of the movement; discontinuous suspension elements as a function of the relative movement; non-linear flexibility of the tyres. The comparison of the results confirmed the validity of the model proposed. Attention is drawn to the fact that the rolling of the tyre markedly decreases the vertical overload by enveloping obstacles. This was reflected by the more severe test-rig tests compared with tests carried out on pavements. Similarly, going over major obstacles (footpaths for example) results in a large vertical acceleration of the centre of gravity. Tests on real pavements showed the marked reduction in the level of vertical accelerations in the whole range of frequencies from 1 to 20 hz when evenness improves, and the disappearance of the rolling movement. /TRRL/

  • Corporate Authors:

    Laboratoire Central des Ponts et Chausees (LCPC)

    Boulevard Lefebvre 58
    Paris Cedex 15,   France  F-75732
  • Authors:
    • Osman, M
  • Publication Date: 1977-5-6

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00194090
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 13 1979 12:00AM