A method of computing road profiles of various roughness by filtering a random binary sequence is developed; the validity of a simulated profile is established by comparing the generated profile characteristics with the power spectral density of measured profiles and also by making comparison with the specification for construction of motorways. A single wheel, laden and unladen, commercial vehicle model is used to examine the dyanmic wheel loads generated by types of road which compare broadly with motorway, Class A, Class B and a profile twice as smooth as a motorway. The simulation results show that over the motorway profile, at vehicle speeds of 64 km/h and 96 km/h, peak impact factors of 1.29 and 1.40 were generated in an unladen model suspension, the values reduced to 1.16 and 1.22 over a profile twice as smooth. In general an unladen suspension produced higher impact factors than when laden. Measured results from an unladen lorry taken over a short length of motorway tended to give higher results than the model, but in the laden condition the measured and model results were in good agreement. Halving the amplitudes of a new motorway profile reduced the percentage RMS load above the steady unladen weight by only 3 per cent at 64 km/h and 5 per cent at 96 km/h. The RMS dyanmic load remains reasonably constant with increased payload. /Author/

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Authors:
    • Laker, I B
  • Publication Date: 1978

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 15 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00174433
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: TRRL Supp Report 360
  • Files: TRIS, ATRI
  • Created Date: Jun 14 1978 12:00AM