Effects of Compliance on Vehicle Handling Properties

This paper reviews various manifestations of compliance and their effects on vehicle handling behavior. It describes the effects of compliance on vehicle steer and roll characteristics and relates them to vehicle safety. Tests to measure the overall steering system compliance and also compliance in individual components of the steering system are described. These measurements are particularly important, since they relate compliance phenomenon to design criteria. The particular significance of steering gear and structure flexibility in steering system compliance is shown. Introduction of compliance in analysis of vehicle roll results in a new concept of roll axis and separation of “kinematic roll axis” from the conventional “dynamic” or “design roll axis”. Measurements and computations illustrating the effects of compliance on “kinematic roll axis” are shown. The effects of compliance on overall vehicle handling behavior are shown in numerical sample calculations, performed by using a six-degrees-of-freedom vehicle handling model.