Abstract

Introducing mechanical springs in parallel with hydro-pneumatic struts can help to design realistic interconnected hydro-pneumatic system for vehicle suspensions. In this dissertation, spring loaded hydro-pneumatic suspension, interconnected in roll plane, is analytically investigated for its ride and handling performance. A highway bus equipped with passive type spring loaded interconnected hydro-pneumatic suspension unit is modeled in roll plane as a four-degree-of-freedom dynamical system subject to excitations arising from road irregularities and roll moment caused by directional maneuvers. The static and dynamic properties of the interconnected suspension are derived and discussed in terms of its suspension rate, roll stiffness, and damping forces. The model is analyzed to examine the effects of percentage load assigned to the springs and hydro-pneumatic struts in view of component size and effective interconnection. The ride and handling performance of selected interconnected suspension are investigated and compared to those of the unconnected and conventional systems for deterministic excitations. The vibration isolation performance characteristics of the interconnected suspension employing a concept of variable sequential damping are further investigated for deterministic excitations.