Optimisation of monotube magnetorheological damper under shear mode

J Braz. Soc. Mech. Sci. Eng.

Mahalingam

2017

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The controllable rheological properties of MR fluid exhibit viscoelastic properties within pre-yield, which are essential for the characterization of MR dampers for the isolation of vibration. In the present work, using particle swarm optimisation (PSO), it is identified that the proportion of MR fluid constituents, fluid gap and current are the parameters which influence majorly on the rheological properties and damping effect of MR damper. Initially, rheological properties of the prepared MR fluid samples are determined using rotational plate-plate type rheometer with the magnetorheological device cell attachment by keeping three levels of gap between the parallel plates. Three different proportions of MR fluid are prepared based on the volume fraction of carbonyl iron particle, i.e., 25, 30 and 35% in the silicone carrier fluid along with 1% of lithium-based grease as stabiliser. The objective function of this optimisation problem is to maximise the shear stress and damping force of the MR damper. The design of experiment (DOE) is employed to obtain the various combinations of parameters and their respective responses. The interaction of the regression model obtained from the DOE is used in PSO to evaluate the optimal parameters. The results indicated that the MR fluid with the particle concentration of 31% is the optimal proportion for MR damper application.

Section: Introductionmentioning

confidence: 99%

Evaluation of optimal parameters of MR fluids for damper application using particle swarm and response surface optimisation

Gurubasavaraju

J Braz. Soc. Mech. Sci. Eng.

Mahalingam

2017

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“…It was found that MRF with optimum mean particle size of 2.9 microns and 74.48% particle loading yielded maximum damping force of 566.9 N for minimum off-state viscosity of 0.354 Pa s at magnetic field strength of 96.9 kA/m. (17) Damping force = 340−3.5 × particle size − 12.5 × particle loading + 0.16 × magnetic field strength + 0.1898 × particle loading × particle loading − 0.00419 × magnetic field strength × magnetic field strength − 0.084 × particle size × particle loading − 0.1025 × particle size × magnetic field strength + 0.0262 × particle loading × magnetic field strength…”

Section: Determination Of Optimal Particle Loading and Size Using Mulmentioning

confidence: 99%

“…Hu et al [16] studied the response of a double-coil MR damper while considering various pistons with different configurations and obtained an optimized design based on length of electromagnetic path resistance and damper core radius. Gurubasavaraju et al [17] performed optimization of geometry of a shear mode monotube magnetorheological damper to maximize magnetic flux density in the shear gap by considering shear gap, number of turns of the electromagnetic circuit, flange length and current as design variables for optimization. Shivaram and Gangadharan [18] reported that magnetic field strength and volume fraction of the iron particles have a major influence on the damping force and that the selection of damping materials should be based on application as there is a significant dependence of frequency on the damping force.…”

Section: Introductionmentioning

confidence: 99%

Determination of optimal magnetorheological fluid particle loading and size for shear mode monotube damper

Acharya

Saini

J Braz. Soc. Mech. Sci. Eng.

2019

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Magnetorheological (MR) fluids belong to a class of controllable fluids, and the composition and concentration of its components govern its magnetorheological properties. In this study, an optimum particle loading (or mass fraction) and size of iron particles in MR fluid for use in a shear mode monotube MR damper were determined based on the damping force and off-state viscosity of synthesized MR fluid samples. Initially, the morphological and magnetic properties of carbonyl iron particles were characterized. Six MR fluid samples were prepared composed of combination of three different particle loadings and two sizes of iron particles. Magnetorheological tests were conducted on these samples to determine the flow curves at off-state and on-state magnetic field conditions. Herschel-Bulkley model was used for mathematical representation of flow curves at different magnetic fields and to determine their dynamic yield stress. Further, a shear mode monotube MR damper with accumulator was designed by using optimization technique for desired dynamic range and damping force. Magnetostatic analysis was performed to determine the magnetic field strength generated in the shear gap at different currents. The damping force was calculated for synthesized MR fluids based on their dynamic yield stress corresponding to the magnetic field strength in the shear gap. Analysis of variance was performed to analyse the significance of independent factors on the damping force and off-state viscosity of MRF. The optimal particle loading and size which yielded maximum damping force with minimum off-state viscosity were determined using a multi-objective genetic algorithm.

“…2a, b, respectively. The shaft of 10-mm diameter is made of SS 304 stainless steel to (7) yp = −0.8239 + 0.3668 × H − 7 × 10 −4 × H 2 [20]. The magnetic field distribution in the MR brake is shown in Fig.…”

Section: Magnetostatic Analysis Of Mr Brakementioning

confidence: 99%

Investigation of magnetorheological brake with rotor of combined magnetic and non-magnetic materials

Acharya

2019

SN Appl. Sci.

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Magnetorheological (MR) brakes are a type of electromagnetic brakes that make use of controllable viscoelastic properties of magnetorheological fluid for braking. The torque capacity of the MR brake depends on the magnitude of magnetic flux density generated in the MR fluid. In this study, the effect of combination of magnetic and non-magnetic materials for rotor disk of MR brake with the objective to maximizing the flux density in the MR fluid gap at the rotor periphery was investigated. Initially, the MR brake rotor disk radius and MR fluid gap thickness were determined by using Genetic Algorithm optimization technique for desired torque ratio and torque capacity. Magnetostatic analyses were performed at different current magnitudes to determine the magnetic field and flux density in the MR brake. Further, to enhance the magnetic field intensity in the MR fluid at the rotor periphery, the rotor was modeled with three different configurations of MR brake with combinations of magnetic and non-magnetic steel and magnetostatic analyses of the MR brake were performed. It was found that the leakage of flux away from rotor periphery was reduced and there is significant increase and concentration of the magnetic field and flux density in the MR fluid gap through the use of rotor disk with combined magnetic and non-magnetic materials which would subsequently increase the torque capacity of the MR brake.