In the dissertation, an analysis of modern test bench methods of pneumatic
tires with their influence on the material properties, as factors for evaluating the performance criteria of the rubber-cord structure, was performed. The main controlled indicators of the deformability of pneumatic tires in general at the modern stage are studied in addition to indicators of the quality of the tire material, its degree of accumulation of damage, using indirect parameters of influence and response, such as pressure, geometry of the contact patch, noise indicators, clutch force, controllability, which hinders the evaluation and improvement of such a high-tech design what are pneumatic tires. Special attention in the dissertation is drawn to the
mechanical properties of the rubber-elastomer matrix, in which various types of damage accumulate. The results of the degree and complexity of damage to materials created by multiple overcoming of artificial obstacles were studied, as a result of which redistribution of loads occurs in fibrous fillers such as: metal cord, fabric and the boundaries of their distribution. Taking into account this circumstance, the method of evaluation of materials for tension, delamination and fractures is applied in the work. The pneumatic tire was considered from the point of view of fractographic evaluations of fracture geometry as fibrous composite materials consisting of a matrix containing reinforcing one-dimensional elements in the form of wire fibers, filamentous fabrics and crystals. It was determined that mechanical
damage to tires during operation does not affect the matrix, but the reinforcing fibers, which are intended to be used as a shear mechanism for braking cracks by the fibers themselves on the adhesion surface of the matrix, with reinforcing fillers to strengthen the volume of the distribution surface in fibrous composite materials. Consider how an independent element of the structure. In the transition layer, connections are formed between reinforcing fibers and matrices through which mechanical stresses are transmitted. The conditions for braking cracks caused by mechanical damage during the operation of automobile tires depend on the structure
of these connections.In the dissertation, a stand is proposed, which is intended for dyamic testing of pneumatic tires and provides determination in laboratory conditions of the service life of the tire, its dependence on the speed of movement of the dynamic radius of the tire and the path traveled by the tire before destruction. The test bench allows
you to reproduce the operating conditions of the tire, including the most extreme in terms of vertical load, skid angle and speed. The method of Lagrange equations was used to build dynamic models of mechanical systems and bodies, and the SIMULINK environment was used for computer simulation of the braking process. The technology of modeling intermediate states of tire deformation and their comparison with the degree of ccumulation of damage as deformation of areas when overcoming obstacles of different geometry during bench tests is proposed.The results of experimental measurements of the elastic deformation of 175/70 R13 car tires at different pressures on a special stand that reproduces the
processes of accumulation of mechanical damage when overcoming road obstacles of complex geometry. The obtained data are used in a new method of evaluatingintermediate states of tire material for predicting mechanical and operational characteristics. The kinematic behavior of a car wheel on a road surface with defined mechanical damage and properties in the Vibrosloy 1 program is shown.This approach is an alternative to a purely theoretical determination of wheel and tire reactions to various obstacles in different driving conditions and external factors. In the work, test tests (power and vibration) were carried out on a multicoordinate stand with a spatial arrangement of drives to reproduce the orientation ofthe wheel in the closest to road conditions. The radial stiffness and the coefficient of
error of tires during radial oscillations for a rotating wheel, depending on the
pumping speed, air pressure in the tire, radial load and vibration frequencies, the damping coefficients of passenger car tires from air pressure and stiffness changes were determined. This approach is an alternative to a purely theoretical determination of wheel and tire reactions to various obstacles in different driving conditions and external factors.
