Abstract
This work experimentally presents the field-dependent hysteresis behavior and fatigue property of an electrorheological (ER) fluid. A Couette type electroviscometer is employed to measure the field-dependent hysteresis of the yield shear stress. The hysteresis is then identified by adopting Preisach model and verified through the comparison between predicted and measured yield shear stress. For the measurement of dynamic fatigue property of ER fluid, a flow mode type apparatus is manufactured to activate the flow motion of ER fluid. Three important dynamic fatigue characteristics; yield stress, current density and response time of ER fluid are experimentally investigated as a function of the operating cycle. In addition, the change of the particle of ER fluid is microscopically observed to advocate the variation of the yield stress.