In this study, the two key factors affecting the thermal performance of the insert rubber and stress distribution on the tire sidewall were analyzed extensively through various performance tests and simulations to promote the development of run-flat tires. Four compounds and two structures of insert rubber were designed to investigate the effects of heat accumulation and stress distribution on durability testing at zero pressure. It was concluded that the rigidity and tensile strength of the compound were negatively correlated with temperature. The deformation was a key factor that affects energy loss, which could not be judged solely by the loss factor. The stress distribution, however, should be considered in order to avoid early damage of the tire caused by stress concentration. On the whole, the careful balance of mechanical strength, energy loss, and structural rigidity was the key to the optimal development of run-flat tires. More importantly, the successful implementation of the simulations in the study provided important and useful guidance for run-flat tire development.

In order to obtain a longer mixing chamber life, a layer of hard alloy coating is generally welded on the surface. However, when the mixing chamber is used for a long time, the surface will be worn due to friction with small fillers and rubber. As a result, there will be a large gap between the mixing chamber and the rotor, which will further affect the quality of the mixed rubber. In this paper, the dispersion process of the reinforcing system is simulated at first, and the mixed rubber samples are obtained from different dispersion stages in preparation for experiments with the chamber material. On this basis, the friction experiment is carried out with the same material as the mixing chamber on the friction experiment machine employed in the improved test part. The experiment shows that the friction and wear between the mixture and metal produced in each mixing stage are different. The wear in the stage with high friction is not necessarily large. The wear will be intensified in the middle and later mixing periods, while the friction will tend to be stable. In this paper, besides the exploration on the friction of fillers and rubber on the mixing chamber in different mixing stages, the most important thing is to change the mixing process of rubber formula, so as to extend the service life of the mixing chamber without changing the comprehensive physical properties of the mixing rubber.