Impact of temperature on tyre hardness

This article deals with the dependence of tyre hardness on temperature. In this study, more than 1 800 temperature-dependent hardness values were measured for 5 samples of summer tyres from different manufacturers and different ages. Using regression analysis, curve equations were determined for each sample. Furthermore, an average curve was determined, which was then applied to the measured values and the error generated by using this average curve was investigated. From the results it is clear that all samples show a polynomial function with a 2nd order polynomial for the temperature range −10 °C to 65 °C. The error of using the average curve reaches values up to 11 % of the average value of the measured hardness of the sample. The lowest error is 2 % of the mean value of the measured hardness of the sample, which corresponds to approximately 1 Shore A. The suitability of using an average curve application depends on the desired output and the required accuracy.