De Facto Standards in Tire Friction

Abstract When evaluating aircraft brake control system performance, it is difficult to overstate the importance of understanding dynamic tire forces—especially those related to tire friction behavior. As important as they are, however, these dynamic tire forces cannot be easily or reliably measured. To fill this need, an analytical approach has been developed to determine instantaneous tire forces during aircraft landing, braking and taxi operations. The approach involves using aircraft instrumentation data to determine forces (other than tire forces), moments, and accelerations acting on the aircraft. Inserting these values into the aircraft’s six degree-of-freedom equations-of-motion allows solution for the tire forces. While there are significant challenges associated with this approach, results to date have exceeded expectations in terms of fidelity, consistency, and data scatter. The results show excellent correlation to tests conducted in a tire test laboratory. And, while the results generally follow accepted tire friction theories, there are noteworthy differences.

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Investigations of Road Wear Caused by Studded Tires

Tire Science and Technology ◽

10.2346/tire.14.420101 ◽

2014 ◽

Vol 42 (1) ◽

pp. 2-15

Author(s):

Johannes Gültlinger ◽

Frank Gauterin ◽

Christian Brandau ◽

Jan Schlittenhard ◽

Burkhard Wies

Keyword(s):

Traffic Safety ◽

Test Bench ◽

Operating Conditions ◽

Test Method ◽

Analytical Models ◽

The Road ◽

Driving Speed ◽

Major Factors ◽

Tire Friction ◽

Variable Operating Conditions

ABSTRACT The use of studded tires has been a subject of controversy from the time they came into market. While studded tires contribute to traffic safety under severe winter conditions by increasing tire friction on icy roads, they also cause damage to the road surface when running on bare roads. Consequently, one of the main challenges in studded tire development is to reduce road wear while still ensuring a good grip on ice. Therefore, a research project was initiated to gain understanding about the mechanisms and influencing parameters involved in road wear by studded tires. A test method using the institute's internal drum test bench was developed. Furthermore, mechanisms causing road wear by studded tires were derived from basic analytical models. These mechanisms were used to identify the main parameters influencing road wear by studded tires. Using experimental results obtained with the test method developed, the expected influences were verified. Vehicle driving speed and stud mass were found to be major factors influencing road wear. This can be explained by the stud impact as a dominant mechanism. By means of the test method presented, quantified and comparable data for road wear caused by studded tires under controllable conditions can be obtained. The mechanisms allow predicting the influence of tire construction and variable operating conditions on road wear.

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A Quantitative Theory for the Computation of Tire Friction Under Severe Conditions of Sliding

Tire Science and Technology ◽

10.2346/1.2148766 ◽

1986 ◽

Vol 14 (1) ◽

pp. 44-72 ◽

Cited By ~ 4

Author(s):

C. M. Mc C. Ettles

Keyword(s):

Friction Coefficient ◽

Flash Temperature ◽

Contact Conditions ◽

Quantitative Form ◽

Heating Effects ◽

Rubber Friction ◽

Viscoelastic Effects ◽

Tire Friction ◽

Pavement Friction ◽

Metal Polymer

Abstract It is proposed that tire-pavement friction is controlled by thermal rather than by hysteresis and viscoelastic effects. A numerical model of heating effects in sliding is described in which the friction coefficient emerges as a dependent variable. The overall results of the model can be expressed in a closed form using Blok's flash temperature theory. This allows the factors controlling rubber friction to be recognized directly. The model can be applied in quantitative form to metal-polymer-ice contacts. Several examples of correlation are given. The difficulties of characterizing the contact conditions in tire-pavement friction reduce the model to qualitative form. Each of the governing parameters is examined in detail. The attainment of higher friction by small, discrete particles of aluminum filler is discussed.

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Tire Friction on Wet Roads

Rubber Chemistry and Technology ◽

10.5254/1.3534982 ◽

1976 ◽

Vol 49 (3) ◽

pp. 862-908 ◽

Cited By ~ 16

Author(s):

K. A. Grosch ◽

A. Schallamach

Keyword(s):

Hydrodynamic Lubrication ◽

Vehicle Control ◽

Critical Conditions ◽

Frictional Properties ◽

Road Surfaces ◽

Road Friction ◽

Tire Forces ◽

The One ◽

Tire Friction ◽

Contact Pressures

Abstract Evidence accumulates that tire forces on wet roads, particularly when the wheel is locked, are determined by the dry frictional properties of the rubber on the one hand and by hydrodynamic lubrication in the contact area on the other. The probable reason why they are so clearly separable is that water is a poor lubricant, tending to separate into globules and dry areas under relatively small pressures. Road surfaces and tire profiles are, therefore, designed to create easy drainage and high local contact pressures. The influence of road friction on vehicle control well below the critical conditions is becoming more clearly understood; but more Investigations are required here, in particular under dynamic conditions.

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Lane-deviation penalty formulation and analysis for autonomous vehicle avoidance maneuvers

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/09544070211007979 ◽

2021 ◽

pp. 095440702110079

Author(s):

Pavel Anistratov ◽

Björn Olofsson ◽

Lars Nielsen

Keyword(s):

Objective Function ◽

Traffic Safety ◽

Autonomous Vehicles ◽

Autonomous Vehicle ◽

Emergency Situation ◽

Change Scenario ◽

Initial Speed ◽

Objective Functions ◽

Double Lane Change ◽

Tire Friction

Autonomous vehicles hold promise for increased vehicle and traffic safety, and there are several developments in the field where one example is an avoidance maneuver. There it is dangerous for the vehicle to be in the opposing lane, but it is safe to drive in the original lane again after the obstacle. To capture this basic observation, a lane-deviation penalty (LDP) objective function is devised. Based on this objective function, a formulation is developed utilizing optimal all-wheel braking and steering at the limit of road–tire friction. This method is evaluated for a double lane-change scenario by computing the resulting behavior for several interesting cases, where parameters of the emergency situation such as the initial speed of the vehicle and the size and placement of the obstacle are varied, and it performs well. A comparison with maneuvers obtained by minimum-time and other lateral-penalty objective functions shows that the use of the considered penalty function decreases the time that the vehicle spends in the opposing lane.

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