Wright, Kraig Richard ShipleyBotha, Theunis R.Els, Pieter Schalk2019-06-182019-08Wright, K.R.S., Botha, T.R. & Els, P.S. 2019, 'Effects of age and wear on the stiffness and friction properties of an SUV tyre', Journal of Terramechanics, vol. 84, pp. 21-30.0022-4898 (print)1879-1204 (online)10.1016/j.jterra.2019.04.001http://hdl.handle.net/2263/70225Accurate tyre models are essential for all full vehicle simulation models. Tyre models are usually parameterised based on measurements on new tyres. This article performs a sensitivity analysis, based on experimental data, to determine the effects of age and wear on a 235/55R19 tyre’s stiffness characteristics as well as the effect of wear on the tyre’s longitudinal friction characteristics. A well-researched and documented method was used to artificially age the tyres. Static tests were performed periodically on the tyre to monitor the changes in stiffness characteristics. Tyres were also subjected to accelerated wear by performing repeated side force versus slip angle and longitudinal force versus slip tests on a coarse concrete surface. The results indicate that the vertical and longitudinal force versus displacement characteristics have small but convincing dependencies on the age and wear. While the aging process was a trustworthy method, the wear process created irregular lateral and circumferential wear which impacted results. Overall the effects of age and wear did not exhibit substantial enough influence on the tyre stiffness to merit a full tyre model update. However, the wear did have a significant effect, in the order of 10%, on the longitudinal friction of the tyre.en© 2019 ISTVS. Published by Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Terramechanics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Journal of Terramechanics, vol. 84, pp. 21-30, 2019. doi : 10.1016/j.jterra.2019.04.001.TyreAgeModellingSensitivity analysisStiffnessWear of materialsConcrete surfaceDisplacement characteristicFriction characteristicsFriction propertiesLongitudinal forceVehicle simulationTiresEngineering, built environment and information technology articles SDG-04SDG-04: Quality educationEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-11SDG-11: Sustainable cities and communitiesEngineering, built environment and information technology articles SDG-12SDG-12: Responsible consumption and productionPostprint Article