Vehicle Steady State Directional Stability
Vehicle Steady State Directional Stability 27.5.1. Cornering Properties to Tyres Cornering Force and Slip Angle When the wheels are in motion tyres are subjected to vertical as well as side (lateral) forces due to road camber, side winds, weight transfer and centrifugal force caused while negotiating a curved paths and steering the vehicle on turns. When a lateral force acts on a road wheel and tyre, a reaction that is a resisting force acts, between the tyres tread contact patch and road surface and opposes any sideway motion. This opposing resisting force is known as the cornering force (Fig. 27.33), whose magnitude is equal to that of lateral force. The increase in this cornering force is roughly proportion to the increase in lateral force until the tyre looses grip with the ground. Fig. 27.33. Tyre trade contact patch distortion when subjected to side force. Beyond this point the proportionality does not hold good with further increase in lateral force so that tyre breakaway is lik