I.11 - Dynamic Ride Properties of a Roll-Connected Vehicle Suspension

Abstract

Vehicle suspension designers are challenged to achieve a compromise between the conflicting dynamic ride, handling, and control performance requirements. While enhancement of rollover threshold and directional control performance requires relatively stiff suspension, softer suspension is desirable to achieve good ride performance. Passive vehicle suspensions are thus invariably designed with soft springs coupled with auxiliary roll stiffness mechanisms to attain a compromise between ride, handling, and control performance and rattle space requirements of the vehicle. Nonlinear analytical model of a vehicle suspension, interconnected in the roll plane, is analyzed in this chapter to examine its properties in the vertical and roll modes. The interconnected suspension system is modeled incorporating the fluid compressibility, nonlinear damping characteristics, multiple chambers of pressurized fluid and gas, and the multi-degrees-of-freedom (DOF) vehicle model. The feedback effects of inter-connecting fluid pipes on the vehicle roll stability and ride performance are established from the simulation results. The dynamic properties of the interlinked suspension with a beam axle are compared with those of an independent strut suspension to demonstrate its performance potentials.