PREDICTION OF TIRE-ROAD FRICTION FROM TEXTURE MEASUREMENTS

A purely theoretical means for predicting tire-road friction has been the subject of research for the past two decades. It is based on a faithful simulation of a pneumatic tire sliding over the wet texture of the road surface. This involved the stress-gross strain analysis of the tread rubber, the effect of shear rate, heat, and lubrication. A device called the Yandell-Mee texture friction meter is described and is the end product of this research. When placed on a road surface, it samples a total texture profile 60 cm long to an accuracy of 0.05 mm and predicts side force and locked-wheel wet friction for three speeds in seconds. Because the result varies only with texture changes, this is an excellent control tool for pavement engineers.