Calculation of Normal Tire Stiffness Using Wheel Rolling Radius at Design Modeling of Machine Movement

The research relates to the field of design of wheeled vehicles, in particular, to the determination of the stiffness of the support wheels during numerical modeling of stable vehicle movement. The purpose of the research is to design a method for calculating the normal tire stiffness using the rolling radius. A method has been developed for calculating the normal tire stiffness of a given free radius at a standardized pressure and at a recommended vertical load. It is proposed to calculate the normal tire stiffness using the rolling radius according to one obtained formula, as well as through the relative deformation according to another obtained formula. The parameters “rolling radius” and “relative deformation” are related by the found dependence. To assess the reliability of the developed method for calculating the normal tire stiffness using the rolling radius, the calculation results are compared with the calculation results based on existing universal computational-experimental dependencies in the form of exponential functions. In total, 196 models of radial truck tires from manufacturer No. 1 (Michelin), 186 models of radial truck tires from manufacturer No. 2 (Goodyear), 49 models of passenger radial tires from different manufacturers (Pirelli, Danlop, Michelin) were considered. The maximum error in calculating their normal stiffness according to the rolling radius method does not exceed 20%, and the average error does not exceed 8%.