Scientific Journal of KubSAU

One of the most important problems facing agricultural production is to increase traction and energy properties and to decrease the deforming effect of wheel propellers of power tractors on the soil. The solution to this problem requires the widespread introduction of computer-aided design systems, which make it possible to predict the towing, fuel, economic, and agro-technological properties of the tractor unit at the design stage. Traction and energy indicators of wheeled agricultural tractors, the level of impact of wheel propellers on the soil are largely determined by the quality of pneumatic tires. The search for the optimal parameters of pneumatic tires, the compliance of tire characteristics with the parameters and operating conditions of the tractor unit, require solving two main problems. Firstly, the development of analytical dependencies describing the process of interaction of elastic wheels with the soil base, depending on the rolling mode of the wheel. Secondly, bringing to the engineering level the methods of calculation and analysis of the wheel propellers and soil system. The work discusses the issues of physical and mathematical modeling of a pneumatic wheel and soil system. It is noted that among the existing approaches to describing the process of interaction of an elastic wheel with soil, it is most preferable to use rheological models that take into account the simultaneous deformation and subsequent restoration of the soil and tire. However, when it comes to the existing models, the formation of the area of the contact patch is associated with a common normal deflection, which is not confirmed by numerous experimental studies. In the present work, the concept of agrotechnological deflection of a pneumatic tire is introduced. The developed model makes it possible to calculate the rut dept, the tangential and radial deformations of the tire, the longitudinal and normal deformations of the base, and the contact pressure under a known normal load on the wheel, wheel rolling radius and speed. We have also presented analytical and experimental dependences of the contact pressure and the rut depth on the size of the agrotechnical deflection