Roll Plane Analysis of Interconnected Hydro-Pneumatic Suspension Struts

This study presents a compact hydro-pneumatic strut design with enhanced working area to reduce the design pressure requirements for suspension applications. The two struts are interconnected in the roll plane to realize enhanced roll properties of the suspension. The feedback effects of the interconnecting pipes on the suspension stiffness and damping properties are derived and discussed. The influences of fluid compressibility on the effective ride and roll properties are also investigated. Asymmetric and variable damping valves are further introduced to realize adequately damped and soft ride, and high low speed damping in the roll mode. Fundamental properties of the proposed interconnected configurations are derived and compared with those of the unconnected struts with an anti-roll bar, in terms of suspension vertical stiffness, roll stiffness, and vertical and roll mode damping. Parametric studies are also performed to study the role of interconnecting parameters on the essential suspension properties. The results indicate that interconnected suspension with inherent enhanced roll stiffness and damping characteristics offers significant potential to improve the dynamic roll performance of heavy vehicles, while retaining soft vertical ride. The effectiveness of the proposed concept is further illustrated through simulation results attained under two different deterministic excitations.Copyright © 2005 by ASME