An alternative model for the evaluation of tyre shear forces under steady-state conditions

Modeling of traction forces generated by wheels is a problem which is being investigated by many years. Several models have been proposed whose complexity depends on the desired accuracy. An evergreen model, which is very often cited and used, is the one proposed by Dugoff et al. in 1970. Despite its simplicity it returns a very good characterization of the phenomena acting on a wheel and has the undoubt advantage of being obtained on the basis of physical considerations. In this paper the original model is revised in order to solve some inconsistencies. Two models have been proposed where the variables conventionally used to characterize the wheel forces, i.e., slip s and side slip alpha, are replaced with a new vectorial variable. A more accurate estimate of the wheel forces has been obtained by removing one simplifying approximation of the original model. Comparisons are proposed between the Dugoff model and the new models.