DETERMINATION OF FORCE TRANSMISSION BETWEEN VEHICLE AND ROAD. AN EXPERIMENTAL CONTRIBUTION IN RELATION TO ITS BASIC EVALUATION.

SIMULTANE ERFASSUNG DER KRAFTUEBERTRAGUNG ZWISCHEN FAHRZEUG UND FAHRBAHN. EIN EXPERIMENTELLER BEITRAG ZU IHRER GRUNDLEGENDEN ERFORSCHUNG

THE NORMAL MODEL ILLUSTRATION USED IN ROAD CONSTRUCTION, WHEREBY A VEHICLE IS SIMPLY SHOWN BY A MASS CONCENTRATED AT ITS CENTRE OF GRAVITY, IS INSUFFICIENT FOR THE PURPOSE OF MAKING PREDICTIONS REGARDING THE ACTUAL FORCES AND FRICTIONAL LOADS ACTING ON INDIVIDUAL WHEELS OF A VEHICLE. TEST DRIVES WERE CARRIED OUT WITH A VEHICLE FITTED WITH MEASURING AND RECORDING EQUIPMENT IN ORDER TO OBTAIN MORE INFORMATION ON THE INTERACTIONS OF FORCES BETWEEN VEHICLE AND ROAD. FOR THIS INVESTIGATION ALL FOUR WHEELS OF THE TEST VEHICLE WERE FITTED FOR THE FIRST TIME WITH FIVE-FUNCTION MEASURING HUBS, SPECIALLY DEVELOPED FOR THIS PURPOSE, WHICH RECORD THREE FORCES AND TWO MOMENTS WITH THE AID OF STRAIN GAUGES. AFTER EXTENSIVE CALIBRATIONS TEST DRIVES WERE CARRIED OUT DURING WHICH MEASUREMENTS WERE RECORDED ON THE RELATION OF FORCES WHEN STARTING, BRAKING AND WHEN DRIVING ON A CIRCULAR PATH AT A UNIFORM SPEED ON A HORIZONTAL PATH. THE RESULTS SHOWED THAT ON STARTING AND BRAKING THE CIRCUMFERENTIAL FORCES AND WHEEL LOADS ARE PROPORTIONAL TO THE BODY ACCELERATION WITH THE EXCEPTION OF THE CIRCUMFERENTIAL FORCES ON THE FRONT WHEELS ON STARTING. THE TANGENTIAL FRICTION LOADINGS SHOW A PICTURE SIMILAR TO THE BODY ACCELERATION; THEY DEVIATE HOWEVER FROM THE MODEL ASSUMPTIONS OF EQUAL FRICTION LOADING FOR ALL TYRE CONTACT POSITIONS. THE ACTIVE FRICTION COEFFICIENTS ARE GREATER AT THE REAR WHEELS WHEN STARTING AND AT THE FRONT WHEELS WHEN BRAKING, CORRESPONDING TO EQUAL FRICTION LOADING. ON A CIRCULAR PATH IT WAS FOUND THAT THE LATERAL FORCES WERE FAIRLY EVENLY DISTRIBUTED OVER ALL FOUR WHEELS. THE DYNAMIC WHEEL LOADS INCREASE ON THE OUTSIDE WHEELS WITH INCREASING RADIAL BODY ACCELERATION AND DECREASE ON THE INSIDE WHEELS WITH RESPECT TO THE CIRCULAR TRACK. IT WAS SHOWN THAT WITHIN THE RANGE UNDER INVESTIGATION THE ACTIVE RADIAL FRICTION COEFFICIENTS, SIMILAR TO THE TANGENTIAL FRICTION LOADS, BEHAVED DIFFERENTLY FROM THE MODEL DERIVED ASSUMPTION OF EQUAL RADIAL FRICTIONAL FORCES. THE INVESTIGATION CONFIRMED RELATIONS WHICH HAD BEEN FOUND WITH THE AID OF VEHICLE SIMULATION SYSTEMS. SUGGESTIONS ARE MADE FOR FURTHER INVESTIGATIONS.

• Corporate Authors:

  UNIVERSITAET KARLSRUHE

  KAISERSTR. 12
  KARLSRUHE,   DEUTSCHLAND BR  D-7500
• Authors:
  • Herring, H E
• Publication Date: 1977

Language

• German

Media Info

• Pagination: 309P

Subject/Index Terms

• TRT Terms: Acceleration (Mechanics); Braking; Force; Heat transfer; Loads; Measurement; Measuring instruments; Torque; Vehicles; Wheels
• ITRD Terms: 5405: Acceleration; 6155: Apparatus (measuring); 1874: Braking; 5421: Force; 5567: Load; 6136: Measurement; 5410: Moment (force); 6731: Transfer (phys); 1255: Vehicle; 1372: Wheel
• Subject Areas: Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 01288940
• Record Type: Publication
• Source Agency: Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV)
• Files: ITRD
• Created Date: Nov 21 2010 1:33AM