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Past experimental studies show that tire–pavement friction values are related to conditions surrounding the tire such as pavement temperature, ambient temperature, contained air temperature, and surface characteristics of the pavement. For measurements taken in different temperature conditions, road agencies generally apply correction factors. These correction factors are based primarily on experience and previous field test measurements that have very limited transferability under different conditions. This paper studies frictional behavior of test tires under different surrounding temperature conditions using finite element analysis. The scope of this research is to analyze the effect of pavement temperature, ambient temperature, and contained air temperature on frictional measurements. Finite element analysis of fully and partially skidding tires over different asphalt pavement surfaces, namely, porous asphalt, ultrathin surface, and stone mastic asphalt, is considered. Observation showed that a higher pavement temperature, ambient temperature, and contained air temperature resulted in a lower hysteretic friction for a given pavement surface and a given tire slip ratio. In contrast, a lower tire slip ratio and a pavement with higher macrotexture resulted in higher friction. This study highlights that a critical combination of these factors will decrease friction significantly.

Grooving of tire tread is necessary to provide sufficient skid resistance for wet-weather driving and to reduce the risk of hydroplaning. Many different groove patterns of tire tread are found in the market. However, their relative effectiveness in reducing hydroplaning risk is generally not known to motorists and highway engineers. The effects of changes in the groove depth of a tire tread's groove pattern also deserve further investigation. This paper presents an analytical study that aims to characterize quantitatively the influence of different tire-tread patterns and groove depths on the hydroplaning behavior of passenger cars. The analysis is performed by means of a computer simulation model with a three-dimensional finite element approach. The following six forms of tire-tread groove patterns are considered: ( a) longitudinal groove pattern, (b) transverse groove pattern, ( c) V-groove pattern with 20° V-cut, (d) V-groove pattern with 40° V-cut, ( e) combined groove pattern consisting of longitudinal grooves and edge horizontal grooves, and ( f) combined groove pattern consisting of longitudinal grooves and 20° V-cut grooves. The analysis shows that a parameter computed as the groove volume per tread area of the tire is a useful performance indicator to assess the effectiveness of various tire-tread groove patterns in reducing vehicle hydroplaning risk. The significance of V-shape grooves is discussed. For vehicular operations involving both forward and lateral movements, the analysis indicates that a combined pattern would provide a good compromise in lowering hydroplaning risk sufficiently in different modes of vehicle movements.

Tire–road interaction addresses safety with respect to braking friction and energy efficiency in the context of rolling resistance. These phenomena are coherent, but their engineering solutions can be contradictory. For example, highly skid-resistant surfaces may not be ideal for fuel economy, but surfaces with low rolling resistance may be prone to skidding. Several experimental and numerical studies have investigated the individual phenomena, but insufficient attention has been paid to studying them coherently. The present study computed braking friction and rolling resistance for various operating parameters and their coherent response for each parameter with the use of a thermomechanical contact algorithm. Micromechanical finite element simulations of a rolling or braking pneumatic tire against selected asphalt concrete surfaces were performed for various operating conditions, such as tire load, inflation pressure, speed, and ambient air and pavement temperatures. The coefficients of braking friction and rolling resistance were found to decrease with the inflation pressure and the temperature and to increase with the wheel load. The braking friction coefficient was found to decrease with the speed, in contrast to the rolling resistance coefficient, which increases with the same parameter. A full-skidding tire registered lower braking friction than a 20% slipping tire. Also, an asphalt surface with higher macrotexture offered higher braking friction and higher rolling resistance, and vice versa.

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