Viscoelastic properties of MR shear thickening fluids

Abstract

Magento-rheological Fluid (MRF) and Shear Thickening Fluid (STF) have separately attracted considerable interest due to their fast and reversible response to an external magnetic field or an abrupt shearing loading. In this paper we fabricated a combined phase of Magento-rheological Shear Thickening Fluid (MRSTF) such that it has an MR and a shear thickening effect. To fabricate it, 14 nm primary size fumed silica particles were suspended in ethylene glycol to form a 25% by weight fraction of STF base. Carbonyl iron particles (3-5 μm) were then mixed with the STF base to obtain four MRSTF samples with weight fractions of 5%, 10%, 20%, and 30%. The viscoelastic properties of all four samples, namely their steady state and dynamic behaviour, were investigated with a parallel-plate rheometer. The relevance of the dynamic behaviour to the stress amplitude, frequency, and external magnetic field were investigated and discussed. MRSTFs behave like linear viscoelastic materials for a small range of stress amplitudes, but at large stress amplitudes they are non-linear viscoelastic or viscoplastic, where the storage modulus gradually decreases with the stress amplitude. Within the linear viscoelastic range of shear stress, MRSTFs behave with linear viscoelastic properties as the frequency increases. MRSTFs also exhibit features of both components, but are more prone to MRF with the inception of external field excitations.

Field-induced rheological characterization of nano/micro-scaled suspensions based on a multi-peak fitting method

“…It is named the strong magnetorheological shear thickening characteristic, which is similar to the Bingham characteristic. 29,30…”

“…Thus, the Bingham characteristics of fluid are enhanced. 30 Therefore, the traditional power law model and Bingham model are difficult to characterize the above-mentioned complex rheological characteristics.…”

A magnetic shear thickening media in magnetic field–assisted surface finishing

“…11 The advantages of MR fluids and STFs are reported in a combined manner by inserting iron particles into the base medium of STFs, which possesses reasonable passive response as well as the MR effect in case of external magnetic field. 12,13 MR fluids cause a viscosity change to a semisolid state in the presence of magnetic field. However, the STFs exhibit potential for changing properties with respect to loading conditions with no external power sources.…”

Throwing motion with instantaneous force using a variable viscoelastic joint manipulator

“…We also suggested using magnetorheological (MR) fluid to suppress the vibration. MR fluid is a functional fluid that can change its own apparent viscosity quickly by magnetic field (Li et al, 2014;Park et al, 2009). Although there are a lot of works about MR fluid such as studying and improving characteristic (Fernandez-Toledano et al, 2015;Goncalves and Ahmadian, 2005;Kordonsky and Demchuk, 1996), we focused on this fluid as a damper in this study.…”