Uncertainty factor analysis of tyre wet grip index for EU and Korea tyre labelling system

EU and Korea governments are running the tyre labelling system from last year. European tyre label displays the grade of three performance parameters (Rolling resistance, wet grip and outside rolling noise). and All tyres sold in Korea will have to carry a label displaying information about two performance criteria (Rolling resistance, Wet Grip). Wet Grip is an important measure of tyre safety. There is growing interest in the wet grip test which is regarded as the most important test item in the tyre label. The wet grip index calculated by wet grip test determines the wet grip rating categories. In this study, uncertainty factors of wet grip index (such as SRTT, test surface friction, static load and water depth) and their effects on the wet grip index are analyzed using the design of experiments. When the uncertainty factors were varied within the test regulation conditions, the variations of wet grip index are analyzed.