Magnetoelastic Buckling of Beams and Thin Plates of Magnetically Soft Material
01 Jun 1972-Journal of Applied Mechanics (American Society of Mechanical Engineers Digital Collection)-Vol. 39, Iss: 2, pp 451-455
About: This article is published in Journal of Applied Mechanics.The article was published on 1972-06-01. It has received 50 citations till now. The article focuses on the topics: Buckling.
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TL;DR: In this article, the authors derived basic equations and boundary conditions for thin elastic plates (carrying static bias E-M fields) and disturbed by dynamical perturbations, both flexural and in-plane motions are considered.
54 citations
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TL;DR: A magnetic “stick–slip” model is proposed to explain the sudden bending transition of an elastic rod experiencing a uniform induction field applied at a normal angle with respect to its long axis and it is demonstrated that the magnetoelastic buckling corresponds to a classical Landau second-order transition.
Abstract: In its simplest form the magnetoelastic buckling instability refers to the sudden bending transition of an elastic rod experiencing a uniform induction field applied at a normal angle with respect to its long axis. This fundamental physics phenomenon was initially documented in 1968, and, surprisingly, despite many refinements, a gap has always remained between the observations and the theoretical expectations. Here, we first renew the theory with a simple model based on the assumption that the magnetization follows the rod axis as soon as it bends. We demonstrate that the magnetoelastic buckling corresponds to a classical Landau second-order transition. Our model yields a solution for the critical field as well as the shape of the deformed rods which we compare with experiments on flexible ferromagnetic nickel rods at the centimeter scale. We also report this instability at the micrometer scale with specially designed rods made of nanoparticles. We characterized our samples by determining all of the relevant parameters (radius, length, Young modulus, magnetic susceptibility) and, using these values, we found that the theory fits extremely well the experimental results for both systems without any adjustable parameter. The superparamagnetic feature of the microrods also highlights the fact that ferromagnetic systems break the symmetry before the buckling. We propose a magnetic “stick–slip” model to explain this peculiar feature, which was visible in past reports but never detailed.
48 citations
Cites background from "Magnetoelastic Buckling of Beams an..."
...Further studies (13, 14) reduced the gap down to 15% by considering the edge effect on the magnetic field....
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TL;DR: In this article, the damping properties of a distributed magnetostrictive layer bonded to an aluminum beam for different boundary conditions and coil configurations are analyzed. But the authors focus on damping characteristics obtained using a distributed magnetic layer and its current carrying actuating coil.
44 citations
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TL;DR: In this paper, the authors studied the buckling behavior of a magnetorheological elastomer (MRE) substrate/layer assembly subjected to a transverse magnetic field and in-plane stress.
Abstract: Magnetorheological elastomers (MREs) are ferromagnetic particle impregnated rubbers whose mechanical properties are altered by the application of external magnetic fields. Due to their coupled magneto-mechanical response, MREs are finding an increasing number of engineering applications. One such application is in haptics, where the goal is to actively control surface roughness. One way to achieve this is by exploiting the unstable regime of MRE substrate/layer assemblies subjected to transverse magnetic fields. In this work, we study the response of such an assembly subjected to a transverse magnetic field and in-plane stress. The layer is made up of a transversely isotropic MRE material, whose energy density has been obtained experimentally, while the substrate is a non-magnetic isotropic pure polymer/gel. An analytical solution to this problem based on a general, finite strain, 2D continuum modeling for both the MRE layer and the substrate, shows that for adequately soft substrates there is a finite-wavelength buckling mode under a transverse magnetic field. Moreover, the critical magnetic field can be substantially reduced in the presence of a compressive stress of the assembly, thus opening the possibility for haptic applications operating under low magnetic fields.
41 citations
Cites background from "Magnetoelastic Buckling of Beams an..."
...In addition to these theoretical investigations, one should also mention associated experimental studies (e.g. Wallerstein and Peach, 1972; Popelar, 1972; Miya et al., 1978)....
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