Mechanics of the Wheel with Tire

The first goal of this chapter is to describe the kinematics of a wheel with tire, mainly under steady-state conditions. This leads to the definitions of slips as a measure of the extent to which the wheel with tire departs from pure rolling conditions. All aspects are discussed in detail and with a critical approach, showing that the use of the slips implies neglecting some phenomena. The slip angle is also defined and discussed. It is shown that a wheel with tire resembles indeed a rigid wheel because slip angles are quite small. The relationships between the kinematics and the forces/couples the tire exchange with the road are investigated by means of experimental tests. The Magic Formula provides a convenient way to represent these functions. Finally, the mechanics of wheels with tire is summarized with the aid of quite a number of plots.