Investigation of Impulse Response of an ER Fluid Viscous Damper

The electrorheological (ER) fluid is a fluid that shows non-Newtonian fluid characteristics when the electrical field is applied. In this study, an experiment of an ER fluid viscous damper, in which an ER fluid is enclosed in the gap of a piston-cylinder system, is carried out to investigate the performances of the ER fluids and the effects of the electric field on the impulse response of the damper when an impulsive force is applied to it. To validate the experimental observations, a theoretical cylinder displacement formula of the damper is derived based on the Bingham approximation and the Stokes flow assumption of the test ER fluids in the damper. The present study shows that, when strength of the applied electric field and concentration of the ER fluids increase, the oscillation amplitudes of the cylinder displacement reduce. In other words, the ER damping effect is improved when the strength of the electric field increases.