Effect of the Normal Force Dependence of Cornering Stiffness on the Lateral Stability of Recreational Vehicles

One of the most important parameters in a vehicle dynamics model is tire cornering stiffness. Recently, Bergman has developed a quadratic expression relating cornering stiffness and normal load by correlating tire test data from four different sources. This quadratic expression, as well as linear and constant approximations of it, are used in lateral stability analyses of a car and of a car/trailer system. It is shown that the change in cornering stiffness with normal load does significantly affect critical speed.