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The free-rolling cornering, straight-line braking, and pull force properties of a small sample of tire specifications is examined. This is done to examine potential differences between the specifications and the statistics of force and moment measurements. Two steer axle specifications, two drive axle specifications, and a trailer specification are considered, In addition, the evolution of properties for one drive axle specification is followed from new to naturally worn-out to retreaded. The summarized data is available from SAE Cooperative Research on electronic media.

The ability to accurately simulate vehicle dynamics behavior with a mathematical model is limited by the quality of the tire model. In fact, the tire is often the single most important component in determining correlation between a mathematical vehicle model and measured experimental results. Tire data for heavy trucks are more difficult and expensive to acquire than passenger car and light truck data, and, consequently, there has been little published experience testing or modeling these tires. This paper shows how the analysts can integrate heterogenous tire modeling methods into one coherent tire model suitable for the simulation of an over-the-road 18-wheel tractor-trailer configuration. The methods used in this paper are: Tire F&M modeling that represents the effect of tread wear, water depth, and speed, as well as combined longitudinal and lateral slip conditions.

The slip circle, COMBINATOR, model was developed to predict combined driving or braking and cornering performance of tires from straight-line torqued data and free-rolling cornering data only. In the original COMBINATOR paper, limited verification was presented. In the current paper, the model is shown to be broadly applicable to tires of all types. This is demonstrated through successful modeling of heavy-duty tires as large as 425/65R22.5 and by modeling of racing tires. The heavy duty tire models and summarized data are available from SAE Cooperative Research on electronic media.

The traction effects of water depth, speed, tread wear, inflation, and load on typical 295/75R22.5 truck tires have been examined in a set of designed experiments conducted on a single pavement. The results have been typified in terms of regression models of aligning moment and lateral force at 4 degrees slip angle plus peak longitudinal force and longitudinal force at slide during braking. The effects of the principal parameters are catalogued. An approximate idea of the effect of the operational and tread wear state parameters on the ability to control vehicle motion is provided within the discussion.