Link between static radial tire stiffness and the size of its contact surface and contact pressure
¹Technical University in Zvolen, Faculty of Environmental and Manufacturing Technology, T.G. Masaryka 24, SK 960 53 Zvolen, Slovak Republic.
²Czech University of Life Sciences Prague, Faculty of Engineering, Kamýcká 129, CZ 165 21, Praha – Suchdol, Czech Republic
The article is devoted to the description of the experimental results regarding the measurement of static radial deformation characteristics of the selected tire and its impact on the size of the contact surface and contact pressure. The given measurement was carried out on the diagonal tire Mitas TS05 10.0/75-15.3 PR10 in the area of the soil test channel. The radial deformation characteristics of the tires in question were determined for inflation pressures of 300 kPa, 220 kPa, 160 kPa and 100 kPa, with a radial stress of the tire varying in the range of 567.9 kg to 1025.09 kg. The prints of the tire’s contact surfaces were made at the same time for the corresponding inflation pressure and the corresponding radial stress. The size of these prints was subsequently planimeterized by the digital polar planimeter Koizumi KP-90N. The values of the medium contact pressure on a solid support were subsequently calculated from the tire radial stress values and the obtained contact surfaces. The calculated static radial stiffness values were obtained through the linearization of the measured deformation characteristics according to Jante. The course of the deformation characteristics and the calculation of static radial stiffness imply that static radial stiffness is significantly dependent on the tire inflation pressure. A suppler tire structure at a lower inflation pressure allows for greater values of the contact surfaces and lower values of contact pressures. This feature can be used when selecting appropriate tire inflation pressures when driving off-road to reduce soil degradation and improving the vehicle’s passability through the terrain.