VERTICAL ACCELERATIONS MEASURED IN SEVERAL TYPES OF CAR TRAVELLING OVER SURFACE DISCONTINUITIES

To types of car were driven at several speeds and with different tyre pressures over a simulated bridge deck expansion joint. Four other tyres of car were driven at several speeds over a bumpy road. Measurements were made of peak-to-peak vertical acceleration on the car floor and at the seat-person interface. The results for all the cars used show that above a certain speed, about 30 km/h, a discontinuity will act as an impulse to the car's suspension system, since the time interval between the passage of the front and rear wheel is short. As a result at speeds above 30 km/h two resonant modes are excited--a 'body heave' at about 1.75 hz, and 'wheel hop' at 10-15 hz. Below this speed the shape of the discontinuity becomes important the effect upon the vehicle occupants of 'wheel hop' is largely filtered out by the car seat. /Author/

  • Corporate Authors:

    Transport and Road Research Laboratory

    Environment Division, Old Wokingham Road
    Crowthorne RG11 6AU, Berkshire,   England 
  • Authors:
    • COOPER, DRC
  • Publication Date: 1973

Media Info

  • Features: Figures; Tables;
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00083128
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: TRRL SR 12 VC Series
  • Files: ITRD, TRIS
  • Created Date: May 1 1975 12:00AM