Enhancement effect of nonferromagnetic particles on the viscosity of magnetorheological fluid under a dynamic magnetic field

Abstract

This study aims to investigate the effect of nonferromagnetic particle content on the properties of the magnetorheological fluid (MRF) under a dynamic magnetic field. A magnetic-induced viscosity calculation model under the temperature field was built. The influence on the viscosity of the MRF made in-house was analyzed by adding different proportions of nonferromagnetic particles, such as glass powder. Experiments show that a certain proportion of glass powder can increase the viscosity of the MRF. When the powder content is less than 10%, viscosity increases as the glass powder content increases. Conversely, viscosity decreases as the glass powder content increases when the content is more than 10% but less than 20%. These results indicate that adding micron glass powder to the MRF can increase the magnetic saturation limit of the MRF under the dynamic magnetic field and improve its settlement resistance by 25.6%.When 10% glass powder is added to the MRF containing 60% iron powder, sedimentation resistance increases by 25.6%. When the magnetic field intensity is 640 mT, the viscosity of the MRF increases by 6.6 times.

Study on the motion of single particle chain in the magnetorheological fluid under the action of traveling magnetic field

“…Meanwhile, it can be seen from figure 7(b) that the particle chain velocity amplitude (2) The effect of TMF moving velocity v s on the motion of particle chain. A different velocity v s of TMF movement will change the number of periods of TMF that the particle chain passes through per unit of time, and according to equation (20), changing v s will lead to a change in the frequency of magnetic field gradient force change on the particle chain, which in turn will change the motion of the particle chain. When the v s is different, the change curve of the particle chain displacement amplitude S A and velocity amplitude • SA is shown in figure 8.…”

“…Nonuniform magnetic fields can affect the shear properties of MRF [15], and the study of the motion of particles in MRF under the action of non-uniform magnetic fields can help to establish a theoretical model of the shear stress-strain characteristics of MRF [19]. On the other hand, the viscosity of MRF changes under the action of a dynamic magnetic field [20], which is mainly related to the interaction between ferromagnetic particles inside the MRF. Meanwhile, the performance of the magnetorheological damper is affected by the non-uniform magnetic field because it changes the structure of ferromagnetic particles inside the MRF [21,22].…”