LINEAR MODELS OF TYRE ENVELOPING PROPERTIES

In many work on modelling automobile ride vibrations the tyres are assumed to follow the surface profile in a point contact. This assumption strongly affects the predictions of the quantities related to the pattern of fluctuation of stochastic processes that model stress and strain in the vehicle suspension such as mean square derivative, mean threshold–crossing rates and extreme values. This difficulty could be eliminated by assuming the line or surface contact between the tyre and the road surface since the real tyre envelopes the surface and attenuates high spatial frequency components. In this paper the tyre enveloping properties were modeled as the linear low–pass filter in the spatial frequency domain. Various types of these filters have been presented. The effect of variations in the filter parameters on the output stochastic processes and their mean square derivative have been considered. The preliminary results of the tyre enveloping properties measurements for the Continental 165–SR–14 tyres were presented.