Experimental study on static yield stress and dynamic shear stress for electrorheological fluids

Yield stress of Electrorheological (ER) fluid is one of the main performance coefficients in application of engineering. So based on the rheology theories, the change laws of static yield stress and dynamic shear stress with shear rate have been researched by our lots of experiments. The research result in this paper shows that the different kind of ER fluid behaves different yield performance especially in the conditions of both post-yield and higher shear rate. From the behavior form of ER effect by experimental investigation, the expressions of static yield stress and dynamic shear stress with shear rate have been defined respectively and the relation between dynamic shear stress and static yield stress also been investigated. Both the highest negative and positive deviation values have been got.