Squeeze behavior of magnetorheological fluids under constant volume and uniform magnetic field

Abstract

In this work the experimental investigation of magnetorheological fluids in squeeze mode has been carried out under constant volume with a self-developed device. The magnetorheological fluids were forced to move in all directions in a horizontal plane as the two flat surfaces came together. A pair of Helmholtz coils was used to generate a uniform magnetic field in the compression gap. The normal forces within the gap were systematically studied for different magnetic field, squeeze velocity, particle concentration, viscosity of carrier fluid and initial gap distance. Two regions of behavior were obtained from the normal force versus gap distance curve: elastic deformation and plastic flow. A power law fitting was appropriate for the relation between the normal force and the gap in the plastic flow. The index of the power law was smaller than that predicted by the continuum theory, possibly due to the squeeze strengthening effect and the sealing effect.

Complex Fluids in Energy Dissipating Systems

“…However, it has been much less exploited than simple shear flow, despite the fact that it is known that the achieved yield stress can potentially be up to ten times larger [68]. Among the few attempts to characterize the rheology of active fluids in elongational flow, there are some studies under squeeze flow experiments using the parallel-plate geometry in a standard shear rheometer with slow approaching speeds between the parallel-plates [69][70][71][72][73][74][75], and only one attempt under pure elongational flow for MRFs [76]. In order to allow the design of new energy dissipating systems based on active-fluids, it is essential to know the relationship between the flow and the external applied magnetic field.…”

Determination of the flow stress of a magnetorheological fluid under three-dimensional stress states by using a combination of extrusion test and FEM simulation

“…Gong et al [8,9] investigated the rheological behavior of MR fluid by compression tests. The work region of MR fluid is a gap of 2.0 mm.…”

Understanding the super-strong behavior of magnetorheological fluid in simultaneous squeeze-shear with the Péclet number

“…5 mm=s) in low-to-mid concentration fluids (Guo et al, 2013;Ruiz-Lo´pez et al, 2013). Most commercial applications, however, require high loading rates and high-concentration (.30%) fluids (De Vicente et al, 2011).…”