Characterization and analysis of magnetorheological damper behavior under sinusoidal loading

Magnetorheological fluids (MRFs) were synthesized to investigate potential enhancements in magnetorheology when replacing magnetic particles with nonmagnetic micro-scale glass beads, that is, to increase yield stress, while reducing density and particle settling rate. Two MRF samples having 40 volume percent (vol%) of particles were synthesized: MRF-40 and MRF-37. MRF-40 had 40 vol% of carbonyl iron (CI) particles, and MRF-37 contained 35.7 vol% of CI particles and 4.3 vol% of glass beads. A comparative study of MRF characteristics was conducted to determine the impact of the nonmagnetic glass beads on yield stress, as well as viscosity, and settling rate. Both MRFs were characterized as follows: 1) magnetorheology as a function of magnetic field, 2) sedimentation rate in a fluid column measured using an inductance-based sensor, and 3) cycling of a small-scale damper undergoing sinusoidal excitations at frequencies of 1 Hz for characterization and 4 Hz for endurance tests. Optical micrographs of the glass beads were taken before and after damper cycling to assess durability. The MRF with glass beads initially doubled the damper yield force (relative to the MRF with no glass beads) at high field strengths in damper tests. This increase in yield force did not persist as the damper was cycled in an endurance test and the glass beads eroded. Fe particle sedimentation rate was reduced by about 4% in the MRF with glass beads.Index Terms-Magnetorheological fluids, nonmagnetic glass beads, yield stress.

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“…The MRF-40 and MRF-37 (with glass beads) samples were studied using a linear stroke MR damper [14]. Data shown in Fig.…”

Section: Damping Behaviormentioning

confidence: 99%

Magnetorheological Fluids Employing Substitution of Nonmagnetic for Magnetic Particles to Increase Yield Stress

2012

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“…Classification of the viscoelastic models is done according to fluid-like or solid-like behavior of the viscoelastic material. The common fluid-like viscoelastic models are viscous dashpot [4,5], Maxwell fluid [6,7], and threeparameter fluid [8,9]. Elastic spring [10,11], Kelvin-Voigt solid [12][13][14], and three-parameter solid [15] are the common solid-like viscoelastic models.…”

Section: Introductionmentioning

confidence: 99%

An experimental evaluation of pre-yield and post-yield rheological models of magnetic field dependent smart materials

et al. 2010

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The rheological behavior of field-dependent smart fluids in both the pre-yield and post-yield regimes is investigated. Typical viscoelastic and viscoplastic models are employed to model the fluids behavior. Viscoelastic models are used widely in the pre-yield regime. Viscoplastic models are also used extensively in both the pre-yield and post-yield regimes. Two smart fluids including a ferromagnetic nanoparticle fluid and an MR fluid are examined here. Using an MCR300 rheometer, the rheological properties of the fluids in both oscillation and rotational mode are measured. In the oscillation mode, the storage and loss moduli versus frequency are measured. In the rotational mode, shear stress, shear rate, viscosity and torque are measured. In the frequency domain, the pre-yield behavior of the ferromagnetic nano-particle fluid is modeled by Kelvin-Voigt solid model. Also, the three-parameter fluid model is used to model the pre-yield behavior of the MR fluid. Two viscoplastic models including Bingham-plastic and Herschel-Bulkley models are selected to model the rheological behavior of fluids in the time domain. Which model is more appropriate depends on the external magnetic field and the shear rate. Both models are used here to model the fluids' behavior. The models properly predict the results observed in the experiments.

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“…A number of mathematical models have been developed to capture this nonlinear behavior [1,14]. For this paper, we are interested in nonlinear models which produce a force output from the MR damper due to two inputs: relative velocity and the control current.…”

Section: Mr Damper Characterizationmentioning

confidence: 99%

“…Many models have been developed to represent this highly nonlinear relationship [1,2,11,13,14]. In this paper, we develop a generalized separable model for the MR damper constitutive relationship.…”

Section: Introductionmentioning

confidence: 99%

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Nonlinear MR model inversion for semi-active control enhancement

2009

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The increased prevalence of semi-active control systems is largely due to the emergence of cost effective commercially available controllable damper technology such as Magneto-Rheological (MR) devices. Unfortunately, MR dampers are highly nonlinear, which presents an often over-looked complexity to the control system designer. The well-known Skyhook Damping control algorithm has enjoyed great success for both fully active and semi-active control problems. The Skyhook design strategy is to create a control force that emulates what a passive linear damper would create when connected to an inertial reference frame. Skyhook control is device independent since it generates a desired control force command output that must be produced by the control system. For simplicity, MR dampers are often assumed to have a linear relationship between the current input and the force output at a given relative velocity. Often this assumption is made implicitly and without knowledge of the underlying nonlinearity. In this paper, we show that the overall performance of a semi-active Skyhook control system can be improved by explicitly inverting the nonlinear relationship between input current and output force. The proposed modification will work with any semi-active control algorithm, such as Skyhook, to insure that the controller performance is at least as good as the performance without the proposed modification. This technique is demonstrated through simulation on a quarter-vehicle system.

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Characterization and analysis of magnetorheological damper behavior under sinusoidal loading

Cited by 21 publications

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Magnetorheological Fluids Employing Substitution of Nonmagnetic for Magnetic Particles to Increase Yield Stress

Magnetorheological Fluids Employing Substitution of Nonmagnetic for Magnetic Particles to Increase Yield Stress

An experimental evaluation of pre-yield and post-yield rheological models of magnetic field dependent smart materials

Nonlinear MR model inversion for semi-active control enhancement

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