Including Roadway and Tread Factors in a Semi-Empirical Model of Truck Tyres

A semi-empirical tire model is described here and used in examining the influences of changes in (a) tire tread depth and (b) pavement mean texture depth and skid number on tire forces. Test results show that changes in tread depth lead to changes in cornering stiffness and the form of the pressure distribution. The ways in which these factors are included in the model and their influences on lateral force characteristics of truck tires are presented and discussed. The influences of tread depth, mean texture depth, and skid number on the sliding friction of truck tires are discussed and equations for representing the frictional characteristics of a worn tire operating on a wet surface (not flooded to a level well over the tops of the road asperities) are presented in an appendix. The body of the paper concludes with a discussion of future approaches for representing frictional effects.