Nonlinear Modeling and Experimental Characterization of Twin-Tube Hydraulic Adjustable Damper: Effects of Cavitation On Hysteretic Behavior

Abstract The hydraulic adjustable damper has attracted wide attention due to its superiorities of low energy consumption, fast response, strong durability, high reliability and simple structure. However, there has been no published detailed analysis about the effects of cavitation on the hysteresis of the hydraulic damper damping output. Furthermore, the existing damper models with simplified assumptions for the cavitation have not been completely studied. Therefore, a nonlinear model of twin-tube hydraulic adjustable dampers ( twin-tube HAD ) is proposed with an emphasis on the cavitation properties. Polytropic change in the gas content, seal friction, oil viscosity and the gas-oil emulsion flowing through orifices or valves are taken into consideration in the model. The cavitation form of twin-tube HAD valve is studied in depth and the dynamic cavitation number of hydraulic oil is formulated as a function of the gas volume fraction, then the damping force is characterized by the gas volume fraction. The model proposed in this paper can be used for accurately analytical investigation and it is useful in reducing damage from cavitation in similar nonlinear equipment. The mathematical model is validated by comparison against experimental results carried out on HONDA-EG8-RH twin-tube HAD in damper test facilities .