Analysis of Force in MR Fluids during Oscillatory Compression Squeeze

Abstract

This study investigates the behaviour of MR fluids in the oscillatory compression squeeze mode. Experiments were performed on commercially available MR fluids in the purpose-built experimental set-up. The influence of MR fluid's properties and magnetic flux density on the force generated during the squeeze mode was investigated.

Magnetorheology: a review

“…Cyclic compression tests were carried out by Ismail et al 198 to interrogate the particle-fluid separation phenomena while Horak et al 199 performed oscillatory compression squeeze mode in a purpose-built experimental setup. A resonant method was used by Kaluvan et al 200 to determine the field dependence of the yield stress in MRFs subjected to squeeze flow.…”

Magnetorheological Fluids Behaviour in Oscillatory Compression Squeeze: Experimental Testing and Analysis

“…Negative sign force values are observed at the lowest oscillation frequency (f = 0.1 Hz) and for I > 2.5 A (B > 400 mT), indicating that, in this case, the MRF 'pushes' the movable measuring plate out also during the return motion. This may be related to the magnetostatic pressure (Horak et al, 2017;Liu et al, 2019;Mazlan, 2007), which may be related to the influence of columnar structures of magnetic particles on the measuring plate in this case. In the case of the MRF-18 and MRF-22 samples, no significant differences in the measured force were observed (approximately FNLmax = −17 N), whereas for fluids with the highest number of particles, double force (FNLmax = −34 N) was obtained.…”

“…Static force is visible in the low enforcement frequency range (up to 0.5 Hz). This process is described in detail in Horak et al (2017) and Horak (2018).…”

“…The oscillatory movement of the upper plate (4) is generated by a connecting rod (8) mounted on a cranked shaft (9), driven by a rotary servomotor (11) with timing belt transmission (10). The range of the oscillating plate movement is determined by the crank value 'e'.…”

“…Analysis of the MRF squeeze working condition is a complex issue. This is primarily due to the large number of factors affecting the process, that is, squeeze-strengthening effect (Liu et al, 2019;Wang et al, 2019), clumping effect or aggregation of MRF particles (Farjoud et al, 2008;Farjoud et al, 2011), complex deformation state (Horak, 2018; Laun et al, 2008), displaced carrier fluid from the squeeze zone (Laun et al, 2008;Szczęch and Horak., 2017), pressure generated in the MRF under the action of the applied magnetic field (Guo et al,2012;Horak, 2018), the cavitation effects (Kuzhir et al, 2008) and the complex force progression during the compression process (Guo et al,2013;Gstöttenbauer et al, 2008;Horak, 2018).…”