Modelling of Fluid-Structure Interactions in the Hydraulic Circuit of Passive Interconnected Suspensions

The pressure changes in the liquid-filled fluid circuits of Hydraulically Interconnected Suspensions (HIS) often lead to vibration of the whole pipeline and associated structures and hence become a source of structural noise, which degrades ride comfort. This paper presents the numerical and experimental investigation into the vibration of this kind of hydraulic circuit. The one-dimensional wave theory is employed to formulate the equations of motions that govern the dynamics of the fluid-structural system. Axial and lateral vibrations as well as the effects of shear deformation on the lateral vibration of the pipe are considered. The dynamic interaction between fluid and pipe is modelled by considering Poisson and junction coupling. The Transfer Matrix Method (TMM) is applied to determine the steady state response of the fluid-structural system, which consists of various pipe sections, hose sections, damper valves, accumulators, supports and joints. Laboratory experiments are performed on a liquid-filled hydraulic circuit with pulse trigger. The measured steady-state responses of the fluid circuit are compared with those obtained from the numerical simulations of the developed hydraulic circuit model. It is found that the developed model of the hydraulic systems including the coupling with boundaries has a reasonable accuracy in the frequency range of interest.