Influence of the Properties of Wheels on the Overall Wheel Characteristics of a Motor Vehicle

摘要

Very important targets for Porsche AG's vehicle dynamics and tyre development are ahigh level of sportiness and a driving safety. In order to achieve targets for all variantsof a vehicle, the influences on driving behavior must be known in detail for all componentsof a chassis. In addition to the applied tyres and the suspension components,the rims have a significant influence on the driving dynamics characteristics. In thesubjective evaluation and analysis of the overall vehicle driving behavior, the propertiesof the entire wheel are always considered as a tyre-rim combination. The vehicle drivingdynamics characteristics of the tyre-wheel-assembly can be influenced by manydesign parameters. So far, the impacts of these design parameters on typical tyre forceand moment characteristics have not been researched in detail.In addition to the usual tuning parameters such as rim width or offset, other propertiesof the wheel such as the coefficient of friction in the tyre to rim contact area, geometriesof the bead seating area as well as the rim stiffness have an influence on the drivingdynamics. In order to investigate the influence of the rim parameters on the tyre andtherefore on the driving dynamics, the property changes of the complete wheel forsurface roughness in the bead area and wheel stiffness are derived from test benchmeasurements. The investigated cornering stiffness and self-aligning-torque stiffnessare both significantly influenced by increasing wheel stiffness and surface roughnessin the contact area between tyre and rim.