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Nonlinear hygrothermal effects on the vibrations of a magnetostrictive viscoelastic laminated sandwich plate resting on an elastic medium

Zenkour Ashraf M., El-Shahrany Hela D.

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 2

692--706

EN

In engineering applications, composite structures supported by elastic foundations are being vastly utilized in various operating environmental conditions. The nonlinear hygrothermal effect on vibration analysis of a magnetostrictive viscoelastic laminated composite sandwich plate rested on two-parameter Pasternak’s foundations is studied in the present article. The material properties of the viscoelastic plate’s layers are considered based on the Kelvin–Voigt model. The governing equation system is derived according to Hamilton’s principle. The analytical solution is obtained to study influences of the hygrothermal change, half wave number, magnitude of the feedback control gain, aspect ratios, thickness ratio, and structural viscoelastic damping coefficients on vibration damping characteristics of the plate including the frequencies, the damping rate, and the deflection. The obtained results indicate that the natural frequency and deflection reduce with increasing the structural viscoelastic damping value. The plate takes a long time for suppressing its vibration due to increasing the hygrothermal factor.

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Incompressible limit for a magnetostrictive energy functional

Gambin B., Bielski W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2013

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Vol. 61, nr 4

1025--1030

EN

The modern materials undergoing large elastic deformations and exhibiting strong magnetostrictive effect are modelled here by free energy functionals for nonlinear and non-local magnetoelastic behaviour. The aim of this work is to prove a new theorem which claims that a sequence of free energy functionals of slightly compressible magnetostrictive materials with a non-local elastic behaviour, converges to an energy functional of a nearly incompressible magnetostrictive material. This convergence is referred to as a Γ -convergence. The non-locality is limited to non-local elastic behaviour which is modelled by a term containing the second gradient of deformation in the energy functional.

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Intelligent epoxy matrix composite materials consisting of Tb0.3Dy0.7Fe1.9 magnetostrictive particulates

Dobrzański L., Wydrzyńska A., Iesenchuk O.

Archives of Materials Science and Engineering

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2009

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Vol. 35, nr 1

33-38

EN

Purpose: This paper presents the acceptable technology to fabricate epoxy-bonded Tb0.3Dy0.7Fe1.9 composites in an effort to produce Tb0.3Dy0.7Fe1.9 bulks with good magnetostrictive properties through the optimization of some fabrication parameters. Design/methodology/approach: Intelligent polymer matrix composite materials consisting of magnetostrictive particulates was obtained by homogenously mixing low viscosity epoxy resin and Tb0.3Dy0.7Fe1.9 powder with grains from 38 to 106 μm. The relationships among the manufacturing technology of these materials, their microstructure, as well as their magnetostriction were evaluated. Materialographic examination of powders morphology and the structure of composite materials were also made. Findings: Composite materials consisting of Tb0.3Dy0.7Fe1.9 particles can extend the possibilities of application the magnetostrictive materials and reduce the cost of their manufacturing. The obtained materials show regular distribution of Tb0.3Dy0.7Fe1.9 powder in epoxy matrix. Research limitations/implications: The advantages of the bonded magnetostrictive composite materials are their simple technology, possibility of forming their properties and lowering manufacturing costs. It is expected that the magnetostrictive properties of Tb0.3Dy0.7Fe1.9 composites presented in this work can be further improved by amelioratethe fabrication parameters. Originality/value: Manufacturing processes of intelligent epoxy matrix composite materials consisting of Tb0.3Dy0.7Fe1.9 magnetostrictive particulates.