Dynamic testing and modelling of the interconnected Moulton Hydragas suspension system

The Moulton Hydragas system interconnects the front and rear wheel on each side of the vehicle with a hydraulic fluid pipe running from one damper chamber to the other.; The Hydragas system from a Rover Group MGF sports car was statically tested to determine the static spring properties. A stiffness matrix was generated that included terms due to individual unit and interconnection effects. Dynamic tests were performed at various sinusoidal amplitudes and frequencies to calculate the damping matrices. One unit was held at its datum position while the other was moved. The damping force vs. velocity diagrams indicated the presence of inertial effects and dynamic stiffness due to rubber hysteresis.; Three models were developed to predict forces transmitted through the units. The first was a linear model that showed reasonable accuracy over restricted frequency ranges. The second model used bilinear spring and damping constants, and was accurate for predicting force at both the front and rear units for frequencies from 1 to 10 Hz. The third model treated the inertial and compressibility effects by inserting a mass into the spring-damper system. The magnitude of the mass was estimated based on the areas of the damper force vs. velocity diagrams. The inertial model did not predict peak forces as well as the bilinear spring/bilinear damper model, but was better able to predict phase lags between the forces at the dynamically excited unit and at the stationary unit. (Abstract shortened by UMI.)...