Experiments and Analysis of the Limit Stresses of a Magnetorheological Fluid

Abstract

This paper presents the results of a rheological test of a commercial magnetorheological (MR) fluid (MRF-132DG). The research includes the problem of measuring and interpreting limit stresses under conditions close to the magnetic saturation of the fluid. Four different limit stresses were determined, two related to the yield point and two related to the flow point. Methods for determining limit stresses, especially due to excitation conditions, were also analysed. The aim of this study is to determine the effect of selected parameters on the values of limit stresses of the selected MR fluid. An additional objective is to highlight the problems of defining and interpreting individual limit stresses in MR fluids, particularly in the context of selecting the values of these stresses for the purpose of modeling systems with MR fluids.

Investigation the Effect of MR Fluid Composition on Properties at Low Strain Ranges

“…In this method, the yield stress is defined as the value of the shear stress at the end of the LVE regime. Here, we define this stress as the point where G differs by more than 5% from its strain-independent value in the LVE regime [36][37][38][39]. The flow stress is defined as the value of shear stress at the crossover point where the storage modulus is equal to the loss modulus (G = G ) (Figure 1).…”