An electrorheological fluid vibration damper

Two types of electrorheological (ER) fluid vibration damper are compared. It was found that a damper using the shear mode of the fluid has a much greater range of damping than a damper operating in the valve mode. A rotary damper using ER fluid in the shear mode was modelled analytically assuming the fluid responded as a Bingham plastic. The resulting nonlinear damping model consisted of an off-field viscous damping component and an on-field Coulomb damping component. To analyse the transient response of the damper an electrically equivalent model was developed. A damper was built and tested and the experimental results are presented.