Arefin Y. Prediction of residual lifetime of car tires in service

The thesis deals with the scientific and practical problem of calculation of residual lifetime of car tires, and with the development of the technique for its technical state diagnostics. The mathematical model of tire is developed on the base of FEM. The static stress-strain state has been analysed and the problems of contact interaction of the tire with road have been solved. Investigation of the stress-strain state of the tire with operational degradation has been carried out. The fatigue lifetime of such tires has been estimated. An approach for investigation of tire deformation at steady rolling has been offered. The approximation of tire rolling resistance is proposed as a function of the velocity, with varying of the level of accumulated fatigue damage. Experimental studies of the regularities of the influence of tires radial stiffness on the vehicle run-out-test have been done. A technique of determination of the degree of tire fatigue damage has been developed based on the analysis of changes in tire static deformation in comparison with the standard model. In addition an express-analysis of the tires technical state has been developed based on the comparison of the changes in the car run-out-test which are made with the degraded and the "new" tires.