Chai, T., Dreyer, J., and Singh, R., "Transient Response of Hydraulic Bushing with Inertia Track and Orifice-Like Elements," SAE Int. J. Passeng. Cars - Mech. Syst. 6(2):1224-1230, 2013, doi:10.4271/2013-01-1927.
Hydraulic bushings are widely used in vehicle applications, such as suspension and sub-frame systems, for motion control and noise and vibration isolation. To study the dynamic properties of such devices, a controlled laboratory bushing prototype is designed and fabricated. This device has the capability of varying different combinations of long and short flow passages and flow restriction elements. Transient experiments with step-up and step-down excitations are conducted on the prototype, and the transmitted force responses are measured. The transient properties of several commonly seen hydraulic bushing designs are experimentally studied. Analytical models for bushings with different design features are developed based on the linear system theory. System parameters are then estimated for step responses based on theory and measurements. Finally, the linear models are utilized to analyze the step force measurements, from which some nonlinearities of the bushing system are identified.