Sasov O. The forecast of the initial characteristics of tyres of superlow pressure for automobiles and tractors

The thesis is devoted to the solution of the question of rising of service life of pneumatic tyres of transportation facilities at the cost of development of effective methods of mathematical simulation and solutions scientificaly grounded in the field of their design. The stress - deformed state of automobile and tractor tyres and also the influence of change of row of structural parameters on their basic exploitation indexes are investigated. The mathematical model for the calculation of stress - deformed state of pneumatic tyres in quasi-statical state is developed that is without taking into account peculiarities of dynamical behaviour of tyre under non stationary rolling. The main equations of vibrations of toroidal shells of pneumatic tyres that contact with elastic base are obtained, the equations of reinforced element of pneumatic tyres in the form of flexible anisotropic plates and shells on the base of hypothesis of Kirhgof - Lyav and with account of deformations of cross shift are received by variation way, the calculations of reinforced element of pneumatic tyres in the form of plates with different pitch as according to the surface of the shell as according to the time are made. The further development of this method of solution of dynamical contact problems accounting one - sided connections on the base of Kirhgof - Lyav model and Timoshenko shift model is proposed. The developed method of calculation of service life of pneumatic tyres accounting temperature conditions of exploitation and amplitude - frequency characteristics of reinforced shell of pneumatic tyres from change of orientation angle of reinforced element it allows to determine the real sizes of their stress - deformed state for more precise definition of calculation of service life of pneumatic tyres. The key words: pneumatic tyres, service life, mathematical model, stress - deformed state, toroidal shells, deformations of cross shift, dynamical contact problem, more precise definition of calculation of service life of pneumatictyres.