TYRE TREAD NOISES AND COEFFICIENTS OF SLIDING OF TYRE/ROAD COMBINATIONS

WITH A NUMBER OF TEST TYRES OF SIZE 165 SR 13 WHICH ARE A REPRESENTATIVE SELECTION WITH RESPECT TO GRIPPING ABILITY, MEASUREMENTS WERE CARRIED OUT FOR TYRE NOISE ON DRY ROAD SURFACES USING THE FKFS SINGLE WHEEL TRAILER AND, ON WET SURFACES, THE SLIDING COEFFICIENT WAS MEASURED USING THE STUTTGART FRICTION MEASURING DEVICE. THE INVESTIGATIONS SHOW THAT THE STRIVING FOR LOW TYRE NOISE DOES NOT COUNTERACT THE DESIRE FOR HIGH SKIDDING SAFETY. FURTHER THE PROBLEM OF TYRE NOISE GENERATION IS INVESTIGATED BY BASIC EXPERIMENTS ON TEST RIGS AND ROAD SURFACES. IT IS SHOWN THAT THE GENERAL VIEW OF THE GENERATION OF TYRE NOISES BY A SEQUENCE OF AIR DISPLACEMENTS FROM CAVITIES IN TYRE TREAD (AIR PUMPING) IS NOT CORRECT. FURTHER IT IS SEEN FROM THE RESEARCH THAT BOUNCING OF THE TREAD LEADS TO VIBRATION IN THE TYRE, WHICH TOGETHER WITH SLIDING ON THE TREAD IS THE CAUSE OF TYRE NOISE. ON EXTREMELY UNEVEN SURFACES, FOR EXAMPLE COBBLED SECTIONS OF ROAD, TYRE VIBRATIONS ARE PREDOMINANTLY THE CAUSE OF TYRE NOISE.