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Integrated analytical-field design method of multi-disc magnetorheological clutches for automotive applications

Kluszczyński Krzysztof, Pilch Zbigniew

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 6

art. no. e139392

EN

This study proposes a new integrated analytical-field design method for multi-disc magnetorheological (MR) clutches. This method includes two stages, an analytical stage (composed of 36 algebraic formulas) and a field stage based on the finite element method (FEM). The design procedure is presented systematically, step-by-step, and the results of the consecutive steps of the design calculations are depicted graphically against the background of the entire considered clutch. The essential advantage of the integrated method with this two-stage structure is the relatively high accuracy of the first analytical stage of the design procedure and the rapid convergence of the second field stage employing the FEM. The essence of the new method is the introduction of a yoke factor ky (the concept of which is based on the theory of induction machines) that determines the ratio of magnetomotive force required to magnetise the entire magnetic circuit of the clutch to the magnetomotive force required to magnetise the movement region. The final value, the yoke factor ky is determined using loop calculations. The simplicity of the developed design method predisposes its use in optimisation calculations. The proposed method can also be adapted to other MR devices analysed in shear mode.

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Rheological properties of MR fluids recommended for use in shock absorbers

Sapiński B., Horak W.

Acta Mechanica et Automatica

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2013

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Vol. 7, no. 2

107--110

EN

The paper summarises the results of laboratory testing of rheological behaviour of (magnetorheological) MR fluids designed for use in shock absorber and vibration dampers. The experiments used a rotational rheometer with an extra chamber inside which a uni-form magnetic field can be generated. Underlying the description of rheological properties of fluids is the Herschel-Bulkley’s model of vis-cous-plastic substances. The aim of the experiment was to determine the shear stress, yield stress, the yield factor and the power-law exponent depending on the magnetic flux density, followed by the comparative study of rheological parameters of investigated fluids.

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Rheological Model Proposition for Granular Structures in Special Conditions

Zalewski R.

Machine Dynamics Problems

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2008

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Vol. 32, No. 3

117-125

EN

The present work mainly focuses on modeling of the mechanical properties of Special Granular Structures (SGS). SGS are structures composed on the basis of loose granular materials encapsulated in a hermetic space. Initially such a material behaves like a traditional plastic mass. When the internal pressure is pumped out of the system, what was baggy bulk transforms into solid (semisolid) state. In some aspects SGS are comparable to MR fluids. Typical rheological model, describing MR fluids and devices working on the basis of it, is adopted to describe cyclic loading experimental results of specially performed SGS testing specimen. In the final part of the paper some numerical results are presented.

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Modeling of Rheological Properties of Special Granular Structures

Zalewski R.

Machine Dynamics Problems

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2008

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Vol. 32, No. 1

113-120

EN

The present work mainly focuses on modeling of the rheological properties of Special Granular Structures (SGS). Typical experimental results acquired for SGS testing specimen have been presented. Phenmenological model, initially built for "smart" fluids has been adopted for description of SGS rheological properties. Comparison with experimental results for SGS indicates that the model is accurate.