The Effects of Age and Wear on the Stiffness Properties of an SUV tyre

With an increasing need for accurate full vehicle models, a sensitivity analysis of the modelling of tyres depending on their age and wear was conducted. This included a sensitivity analysis into the accuracy of acquiring the tyre stiffnesses on a static test setup. An FTire model is developed with the aim to update this model with basic tests to give a more accurate representation of the aged or worn tyre. A well-researched and documented method is used to artificially age the tyres. During the aging process the tyre was statically tested to monitor the potential changes in characteristics. Tyres were also worn on a dynamic test setup and periodically tested to monitor the property changes. These tests included both static and dynamic measurements. The results indicate that the vertical and longitudinal stiffnesses of the tyre have convincing dependencies on the age and wear of the tyre. While the aging process was a trustworthy method, the wear process created irregular wear across and around the tyre subsequently skewing the results. Simple methods of updating the FTire tyre model without re-parameterising the model completely, was found to be effective in accounting for age and wear.Dissertation (MEng)--University of Pretoria, 2017.Mechanical and Aeronautical EngineeringMEngUnrestricte