Dynamic Testing and Modeling of an MR Squeeze Mount

Abstract

MR fluid squeeze mode investigations at CVeSS have shown that MR fluids show large force capabilities in squeeze mode. It was found that MR fluids in squeeze mode may be used in a wide range of applications such as engine mounts and impact dampers. In these applications, MR fluid is flowing in a dynamic environment due to the transient nature of inputs and system characteristics. The research presented in this article undertakes the problem of dynamic testing and modeling of MR fluid squeeze mounts. Dynamic tests of an MR mount are studied for different applied currents, initial gaps, frequencies, and excitation amplitudes. An effective mathematical model of the MR squeeze mount for steady-state testing was built which includes the effect of the inertia of the fluid. The results show that the compression force and the area of the hysteresis loop increase with the increase of excitation amplitude or applied current and it will decrease with the increase of frequency or initial gap. Also, the inertia effect becomes more significant for higher displacement frequencies. The mathematical model agrees with the test data very well during the compression process and it can be used for the dynamics analysis and the real-time control.

Dynamic characteristics of magnetorheological fluid squeeze flow considering wall slip and inertia

“…As the flow mode and the shear mode, the magnetic chain is broken by shear force and it is broken by squeeze force as the squeeze mode. And the squeeze mode, under the same external excitation, can produce largest response force, showing extensive application potential (Chen et al, 2016b; Mazlan et al, 2007; Sapiński and Gołdasz, 2015; Vieira et al, 2003; Zapoměl et al, 2017; Zhang et al, 2011), and the work range of squeeze mode is smaller than the other modes (Wang et al, 2005).…”

“…Mazlan et al (2007Mazlan et al ( , 2008aMazlan et al ( , 2008bMazlan et al ( , 2009Mazlan et al ( , 2011 further revealed the effects of squeeze velocity, squeeze gap, and current intensity. Zhang et al (2011) studied the MRF dynamic behaviors up to 50 Hz. The morphological changes of MRF during the squeeze process were observed and the internal physical state changes of MRF in squeeze mode were explained by Sapin´ski et al (2014) and Ismail et al (2012).…”

“…Modeling on MRF device dynamics is another hot topic in these years. The Bingham constitutive equation is used widely since good balance between computing speed and accuracy (Farjoud et al, 2009(Farjoud et al, , 2011Janusz and Sapin´ski, 2011;Zhang et al, 2011). And the MRF constitutive equation was expressed through the Newtonian behavior at low shear rate and Herschel-Bulkley at large shear rate by Susan-Resiga (2009).…”

“…Goldasz and Sapin´ski (2012) designed an MRF squeeze mount and divided its dynamic model to get its stiffness and damping coefficient. Zhang et al (2011) and Chen et al (2016a) solved and analyzed the inertial force, demonstrating the inertial force has a great influence on the MRF squeeze dynamic characteristics under high-frequency excitation, and the coupling of inertial force and viscous force should be extended.…”

“…Hence, we attempt to investigate the effects of inertial force, yield, and wall slip on the dynamic behavior of MRF squeeze flow by experimental test and theoretical analysis. In the previous research (Zhang et al, 2011), we established a squeeze model based on the Bingham constitutive, in which the inertial force and the vertical force based on the MR behavior were solved separately. In this article, a dynamic characteristic theoretical model of MRF squeeze flow with inertial force, yield, and wall slip is derived and the mechanism of MRF squeeze flow is explored.…”