TIRE - CONTRIBUTION TO TIRE - PAVEMENT INTERACTIONS REQUIREMENTS WITHIN THE BALANCE OF PERFORMANCES REQUIRED FOR A SUSTAINABLE MOBILITY (Communication limited to passenger car tires) Dr. Joachim Neubauer TYROSAFE / HAMBURG 18.02.09
What are the interactions between Tire and Road to produce the Vehicle-Tire-Road performances? Pollution: NOISE Safety: WET- GRIP To what extent can tire manufacturers, road manufacturers, and road agencies act independently, or should they join their efforts to make progress on: Emissions: ROLLING RESISTANCE CO 2 NOx Natural resources: WEAR
Mechanisms Vibrations Indentation Percussion Acoustic network Slippage 1mm - 1cm Road Road texture Ground Attenuation Tire Compound viscoelasticity Architecture Tread design Organ Pipe Air Squeezing Ampli. / horn effect Micro slippage High interaction between Tire and Road characteristics
Contributors to Noise level variability on the road network Road Surface Vehicle Speed Bulletin des Laboratoires des Ponts et Chaussées n 224, janvier-février 2000 Acoustic level In db (A) 4 db (A) 10 db (A) 60 80 Speed in km/h Road surface is the biggest contributor to noise level variability : low noise pavement technologies are available Traffic regulation can also be a powerful leverage
Mechanisms Indentation Viscoplaning Hydroplaning 1µm - 1mm 1mm - 1 cm 1cm - 1dm Road Road texture Road texture & pollution Transversal profile & drainability Tire Compound visco-elasticity Water storage by tread pattern Water flow by tread pattern The friction coefficient is highly dependent on road texture, road pollution, speed, water depth, temperature, and tire wear level
Braking distance: influencing factors Order of magnitude of influencing factors on braking distance Influencing factor on bracking distance (order of magnitude) Vehicle sold on the market Tyres sold on the market (wet) Tyres sold on the market (dry) Road friction (CFT) Ambiant temperature [5 C-25 C] Tread depth 8mm vs 1.6mm Water height (1mm/humid) 80-20kph 0% 20% 40% 60% 80% 100% % variation of wet braking distance performance
Mechanisms Belt: 20 % Tread-bulk: 35 % Tread-road contact 15% Inner liner & casing: 10 % Bead / Sidewall: 20 % 1mm - 1cm Indentation The interaction between Tire and Road characteristics is low
Mechanisms Indentation Friction energy Stresses per rib 1µm - 1mm Road Road texture Tire Compound viscoelasticity Pressure map & tread rigidities Contact shape equilibrium The mileage has a very strong averaging effects which frees the tire design choices from road surface characteristics consideration
Tire-Road Interaction High None High benefit of local pavement solutions Progress in the hands of tire manufacturers, road manufacturers, and road agencies Wet Grip Safety Noise Pollution Low impact of pavement characteristics Progress mainly in the hands of tire manufacturers Natural resources Emissions
Introduction Wet Grip Noise Major breakthroughs on Noise, RR, & Wet-Grip will include new tire & road technologies Tire Manufacturers RR & Noise & & Wet-Grip Road Manufacturers Road Agencies
Introduction Wet Grip Noise Sustainable mobility as a result of improved key - tyre - performances Fuel economy Process Technology Full Silica Mixing Standard Tyre Performances life Wet - Grip New Durable Security Compound
Introduction Wet Grip Noise Thanks for your attention! And for all reasons : Remember that the right pressure is a key success factor for the performance of your tires and for long tires life