MEASUREMENT OF THE DYNAMIC TIRE FORCES OF A LARGE TRUCK

THE DYNAMIC TIRE FORCES EXERTED BY A LARGE TRUCK ON AN INSTRUMENTED SECTION OF PAVEMENT ARE BEING MEASURED. PARTICULAR ATTENTION IS GIVEN TO AN ANALYSIS OF THE PROBLEMS INVOLVED IN OBTAINING PRESSURE RECORDS AND THE DEVELOPMENT OF DATA PROCESSING PROCEDURES TO CONVERT THESE RECORDS TO FORCE RECORDS. AS THE TRUCK TRAVERSED A REGION NEAR A TEST POINT IN THE PAVEMENT, THE TIRE PRESSURES IN ITS INNER AND OUTER LEFT DUAL TIRES WERE RECORDED WITH TIME. TWO PROCEDURES ARE USED TO CONVERT PRESSURE RECORDS TO FORCE RECORDS FROM AN F/P /FREQUENCY RESPONSE TRANSFORM/ VS. FREQUENCY CALIBRATION. THE F/P /FORCE EXERTED ON THE TIRE DIVIDED BY TIRE PRESSURE/ CALIBRATION IS OBTAINED BY DROPPING A RIGID BEAM, UPON WHICH THE TEST TRUCK IS RESTING, A KNOWN DISTANCE AND SIMULTANEOUSLY RECORDING THE FLUCTUATING TIRE PRESSURE WITH TIME AND THE FORCE EXERTED BY THE TIRE ON THE BEAM. THE FORCE-TIME AND PRESSURE-TIME PLOTS ARE THEN TRANSFORMED TO FORCE-FREQUENCY AND PRESSURE- FREQUENCY PLOTS BY USE OF THE FOURIER TRANSFORM AND THE NUMERICAL INTEGRATION PERFORMED USING SIMPSONS RULE. THE RATIOS OF THE MAGNITUDES OF THE TRANSFORMED FORCE AND PRESSURE RESPONSES ARE PLOTTED AGAINST FREQUENCY FOR EACH OF THREE DROP HEIGHTS AND AN ERROR CRITERION APPLIED. PREDICTED AND EXPERIMENTAL FORCE POWER SPECTRA ARE CALCULATED FROM PAVEMENT ELEVATION POWER SPECTRA AND FROM MEASURED TIRE FORCES RESPECTIVELY. THE CONCLUSIONS ARE /1/ THAT FOR SMALL DISPLACEMENTS THE VEHICLE SUSPENSION SYSTEM DURING THE CALIBRATION TESTS MAY BE APPROXIMATED AS A LINEAR SYSTEM, /2/ THE DISTRIBUTION OF FORCE BETWEEN INNER AND OUTER DUAL TIRES IS STRONGLY INFLUENCED BY THE TRANSVERSE ROAD PROFILE, /3/ THE DYNAMIC COMPONENT OF THE TOTAL TIRE FORCE /DYNAMIC PLUS STATIC/ OF ONE WHEEL OF THE TRUCK WAS AS GREAT AS THE TOTAL FORCE OF ONE WHEEL OF AN AUTOMOBILE, AND /4/ PREDICTED FORCE POWER SPECTRA WERE GENERALLY HIGHER THAN EXPERIMENTAL VALUES.

• Supplemental Notes:
  • Hpr-1/3/, STATE III-1, BPR 8
• Corporate Authors:

  Purdue University

  School of Aeronautics and Astronautics
  West Lafayette, IN  United States  47907
• Authors:
  • Kibbee, G W
• Publication Date: 1965-9

Subject/Index Terms

• TRT Terms: Beams; Dynamics; Force; Fourier transforms; Information processing; Instrumentation; Measurement; Pavements; Records management; Time; Tires; Trucks
• Uncontrolled Terms: Profiles; Records
• Old TRIS Terms: Dynamic conditions
• Subject Areas: Finance; Highways; Motor Carriers; Pavements; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00222544
• Record Type: Publication
• Files: TRIS
• Created Date: May 1 1994 12:00AM