Title: Experimental estimation of fatigue resistance of rubber-cord composite under orthogonal to reinforcement deformation be-fore and after artificial aging
Abstract: The paper defines parameters of the fatigue resistance of the rubber-base composite with textile reinforcement and the regularity of their changes due to aging. That material is presents pneumatic tire's carcass layer. The research has carried out experimentally using a modern measuring system INSTRON. Tests have been carried out with specimens on cyclic tensile uni-directional deformation in a displacement control condition. The amplitudes of deformation was fixed and the specimens cycles around the set middle level of deformation, that avoids the effect of specimen buckling. The results of the tests on cyclic deformation up to failure at different amplitudes of the load have been approximated by the straight lines in a double logarithmic coordinates, i.e. classical Wohler fatigue curves were obtained. The specimens before and after aging have been studied independently. The aging of samples was gained artificially using the procedure of thermal prolonged exposure in a heat chamber at a fixed temperature. Based on the recommendations given in the literature, the samples were kept for 6 days at 80 °C, that corresponds to the natural aging of this material at a room temperature during the 3 years. Comparative analysis of fatigue curves obtained for samples of the material before and after artificial aging shows that the slope of Wohler curves does not change over the time, but the basic number of cycles to failure is significantly reduced. The parameters of the approximations for fatigue curves are obtained relatively for the amplitudes of strains and Cauchy true stresses.