The traction performance of tires is discussed based on vehicle type, climate conditions, vehicle speed, tire inflation and more as it relates to a variety of applications, including racing, aircraft, and medium- and heavy duty trucks.

Traction Key to Skid, Spin Resistance

Traction controls the propelling, cornering and braking of a vehicle through the friction of the tire treads and the road surface, hence providing safety. The field of traction is complex, particularly when considering the road/tire/vehicle/driver system interactions involved.

The traction performance of a given vehicle depends on the following:

• tire friction properties (particularly tread hysteresis and hardness) from new to replacement time;

• vehicle properties from new to replacement time;

• road surface friction properties, from new to polished/worn by traffic, and from smooth to bumpy;

• vehicle speed, driver inputs and reactions;

• climatic conditions, hot/cold (summer vs. winter), winds, snow- or ice-covered road surfaces, rainfalls and road surface water drainage efficiency;

• tire tread design, footprint shape, dimensional proportions and amount of tread depth remaining; and

• tire type, load and inflation pressures.

Mathematical modeling and virtual testing of tires

In spite of the power of scientific means available to engineers today, tires remain extremely difficult, if not impossible, to model to the level of effectiveness required to yield tangible/reliable results representing real world situations.

To ease their tasks, and to attempt to reduce costs, engineers rely on assumptions, probability and statistical analysis, computer software algorithmic programs, etc., all in an attempt to correctly rate road/tire/vehicle/driver system operational characteristics. This includes the use of virtual testing, an approach which, at times, misses typical real world operating conditions. Mathematical modeling or forecasting, in fact, never gets to the point where it is 100% accurate.

As for human factors, they simply cannot be modeled with mathematics. So, when excessive faith and unrealistic optimism are placed on this approach, unpleasant surprises can arise, particularly once the product is in the public’s hands.

Although expensive and time consuming, real world road/tire/vehicle/driver system testing still yields the best results, but must be conducted by hands-on development engineers experienced in this field. This expertise, which takes years to acquire, is becoming harder and harder to find these days, and reliable interpretations of test results are paramount.

[source - trucknews.com]