Investigation into the Effects of Suspension Design on Stability of Light Vehicles

A variety of suspensions are used in light vehicles and they affect dynamics of vehicles in various ways. The components of lateral and longitudinal weight transfers, which depend upon suspension design, influence the wheel normal loads, tire characteristics, and tire-roadway limits of adhesion which in consequence determine vehicle stability.

Modeling procedures for nonlinear kinematic and dynamic analysis of 25 commonly used light vehicle suspensions have been developed and applied to investigate the spatial movement of vehicle roll axis. A nonlinear tire model based on a friction ellipse concept and capable of accepting CALSPAN tire data has been developed to compute cornering forces as functions of slip angle variables, normal loads, tire adhesion characteristics and skid numbers. Development of handling simulation models of light vehicles which utilize the dynamics of specified suspensions to investigate a transient and steady state response of vehicles in combined, cornering and braking or accelerating maneuvers is presented. The calculated results emphasize the necessity of incorporating into the vehicle model variation in suspension designs while investigating the stability of vehicles.