Study of the Factors Affecting the Friction of Tread Compounds on Ice

Abstract

The friction of tread compounds on ice is affected to a great extent by the methods and conditions of measurement. As velocity of sliding is increased from zero to about two centimeters per second, there is an increase in friction, after which there is a gradual decrease with further increase of velocity. Static friction depends on the length of time the sample is in stationary contact with the ice, and is of little practical significance. Of the test variables studied, temperature has the greatest influence. At the lowest temperatures used, −30 to −40° C, the coefficient was approximately double that usually observed slightly below the freezing point. Friction was also found to vary with pressure. An empirical equation of the form,k=C1−C2 log P, was found to fit results in many cases. Minor differences were noted, resulting from changes in sample shape and surface treatment. When testing conditions were held constant, it was found that several variables in the samples themselves affected the friction. The type of polymer used had a definite effect. Of about equal importance was hardness. In similar compounds the softer samples had higher coefficients of friction. The unusual frictional characteristics of rubber sliding on ice may be explained by taking into account the water layer formed between the sliding surfaces. The melting of ice to form this water layer takes place because of the heat generated by the work done against friction. The friction itself is believed to be caused by alternate welding and breaking of junctions between surface asperities. Although the process is initiated in part by pressure melting, that phenomenon has only minor importance after the motion is in progress.

Morphology of ice wear from rubber–ice friction tests and its dependence on temperature and sliding velocity

“…All data rises with falling temperature from a minimum at 0 • C. Data from studies by Conant et al [26] and Roberts (nitrile rubber) [27] compare favourably with those here in both magnitude and trend, showing a rise to an apparent maximum followed by a fall in μ with decreasing temperature. Data from Roberts (isoprene) [27] and Wilkinson [13] also rise with falling temperature, but do not exhibit the maximum within the temperature range reported.…”

“…Fig. 11 shows a comparison of two selected sets of our μ-temperature data with those found in three studies made under comparable conditions [13,26,27]. The parameters for each study are summarized in Table 2.…”

“…There is also a pronounced velocity dependence with low friction (μ < 0.3) at both low and high velocities with maxima of high μ at intermediate velocities [12,13]; the maxima are associated with the viscoelastic properties of rubber which are significant at and above T g [14] and are related to the internal rubber friction [8].…”

Sand as a friction coefficient improver on asphalt ice layers

“…It means varying the rubber slider temperature due to the air temperature. Temperature °C Venkatesh 25 Southern 26 Wilkinson 27 Higging et al 28 Alex Klein-Paste 10 George L. Blaisdell…”

A Study of the Friction Characteristics of Rubber Thermo-Mechanical Coupling

“…Therefore, the tire’s friction performance directly affects the vehicle’s handling performance, which, in turn, impacts the safety of the passengers and their vehicle. Rubber is the primary component of a tire, and its dynamic friction characteristics are influenced by a number of factors, such as speed, pressure, temperature, sideways deflection angle, and sideways inclination angle, with temperature in particular having a significant effect on these characteristics [ 1 , 2 , 3 ]. During driving, tires experience high-frequency deformation due to the hysteresis heat and friction with the ground.…”