TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel A1 - Saveliev, Dmitry V. A1 - Belyaeva, Inna A. T1 - Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold JF - Physica A: Statistical Mechanics and its Applications N2 - In composite materials, with field-dependent restructuring of the filler material (changes in the mutual arrangement of inclusions), the presence of an external magnetic field induces anisotropy of the dielectric properties, even if the composite is isotropic in the absence of an external field. A modified effective medium approximation is proposed for the calculation of the components of effective permittivity within a class of composites with reconfigurable microstructure, where both phases (the filler and the matrix) are isotropic and the inclusions have spherical shape. The effective physical properties are calculated in the parallel and perpendicular directions to an applied field. The appearance of the anisotropy of the permittivity is simulated by the introduction of two not-equal, possibly variable (field-dependent) percolation thresholds. The implications, of the proposed theoretical approach, are demonstrated for the case of the dielectric properties of magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of micrometer-sized magnetic inclusions can significantly change in an applied magnetic field. A reasonable agreement between theory and experiment at a measurement frequency of 1 kHz is found, and is improved in comparison to the previous models. The components of the effective permittivity tensor, characterizing the dielectric properties along the direction of the applied magnetic field and in the orthogonal direction, grow with an increasing field. This growth is more pronounced for the permittivity component in the field direction. The possible extensions of the theoretical model and future directions of research are discussed. The presented theoretical approach can be useful for the application-driven development of a number of smart materials, in particular electro- and magnetorheological gels, elastomers and fluids. KW - Effective medium theory KW - Magnetoactive elastomer KW - Percolation threshold KW - Anisotropy KW - Effective permittivity KW - Random heterogeneous medium Y1 - 2020 U6 - https://doi.org/10.1016/j.physa.2020.125170 VL - 560 IS - December PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Podlasov, Sergii A1 - Shamonin (Chamonine), Mikhail T1 - Isotropic inertia tensor without symmetry of mass distribution JF - American Journal of Physics N2 - Conventional calculations of the inertia tensor in undergraduate physics course are usually done for highly symmetrical bodies. Students might therefore get the impression that the moment of inertia about any axis through the center of mass is the same only for bodies with the highest degree of symmetry relative to this point, e.g., for spheres. A simple, seemingly counterintuitive example is presented, showing that the moment of inertia of a non-regular body, here an assembly of material points, can be the same about any axis passing through its center of mass. Y1 - 2021 U6 - https://doi.org/10.1119/10.0005416 VL - 89 IS - 10 SP - 916 EP - 920 PB - AIP Publishing ER - TY - JOUR A1 - Kalita, Viktor M. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zorinets, Denis T1 - Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers JF - Physical review E N2 - The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016)]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Pade approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles. KW - BEHAVIOR KW - composites KW - DEPENDENCE KW - FERROGELS KW - MECHANICAL-PROPERTIES KW - MICROSTRUCTURE KW - Polymer KW - PURE SHEAR KW - RHEOLOGY KW - SENSITIVE ELASTOMERS Y1 - 2017 U6 - https://doi.org/10.1103/PhysRevE.95.032503 VL - 95 IS - 3 PB - American Physical Society ER - TY - JOUR A1 - Bodnaruk, Andrii V. A1 - Brunhuber, Alexander A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Snarskii, Andrei A. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Shamonin (Chamonine), Mikhail T1 - Temperature-dependent magnetic properties of a magnetoactive elastomer: Immobilization of the soft-magnetic filler JF - Journal of Applied Physics N2 - The magnetic properties of a magnetoactive elastomer (MAE) filled with mu m-sized soft-magnetic iron particles have been experimentally studied in the temperature range between 150 K and 310 K. By changing the temperature, the elastic modulus of the elastomer matrix was modified, and it was possible to obtain magnetization curves for an invariable arrangement of particles in the sample and in the case when the particles were able to change their position within the MAE under the influence of magnetic forces. At low (less than 220 K) temperatures, when the matrix becomes rigid, the magnetization of the MAE does not show a hysteresis behavior, and it is characterized by a negative value of the Rayleigh constant. At room temperature, when the polymer matrix is compliant, a magnetic hysteresis exists where the dependence of the differential magnetic susceptibility on the magnetic field exhibits local maxima. The appearance of these maxima is explained by the elastic resistance of the matrix to the displacement of particles under the action of magnetic forces. KW - BEHAVIOR KW - composites KW - FIELD KW - GELS KW - hysteresis KW - Magnetorheological elastomers KW - MICROSTRUCTURE KW - PERMEABILITY KW - RAYLEIGH LAW KW - STRAIN Y1 - 2018 U6 - https://doi.org/10.1063/1.5023891 VL - 123 IS - 11 PB - AIP Publishing ER - TY - JOUR A1 - Kalita, Viktor M. A1 - Snarskii, Andrei A. A1 - Zorinets, Denis A1 - Shamonin (Chamonine), Mikhail T1 - Single-particle mechanism of magnetostriction in magnetoactive elastomers JF - Physical Review E N2 - Magnetoactive elastomers (MAEs) are composite materials comprised of micrometer-sized ferromagnetic particles in a nonmagnetic elastomermatrix. Asingle-particle mechanism ofmagnetostriction in MAEs, assuming the rotation of a soft magnetic, mechanically rigid particle with uniaxial magnetic anisotropy in magnetic fields is identified and considered theoretically within the framework of an alternative model. In this mechanism, the total magnetic anisotropy energy of the filling particles in the matrix is the sum over single particles. Matrix displacements in the vicinity of the particle and the resulting direction of the magnetization vector are calculated. The effect of matrix deformation is pronounced well if the magnetic anisotropy coefficient K is much larger than the shear modulus mu of the elastic matrix. The feasibility of the proposed magnetostriction mechanism in soft magnetoactive elastomers and gels is elucidated. The magnetic-field-induced internal stresses in the matrix lead to effects of magnetodeformation and may increase the elastic moduli of these composite materials. KW - BEHAVIOR KW - Deformation KW - DEPENDENCE KW - FERROGELS KW - HOMOGENEOUS MAGNETIC-FIELD KW - magnetodeformation KW - MICROSTRUCTURE KW - SENSITIVE ELASTOMERS Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevE.93.062503 VL - 93 IS - 6 PB - American Physical Society ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel T1 - Effective medium theory for the elastic properties of composite materials with various percolation thresholds JF - Materials N2 - It is discussed that the classical effective medium theory for the elastic properties of random heterogeneous materials is not congruous with the effective medium theory for the electrical conductivity. In particular, when describing the elastic and electro-conductive properties of a strongly inhomogeneous two-phase composite material, the steep rise of effective parameters occurs at different concentrations. To achieve the logical concordance between the cross-property relations, a modification of the effective medium theory of the elastic properties is introduced. It is shown that the qualitative conclusions of the theory do not change, while a possibility of describing a broader class of composite materials with various percolation thresholds arises. It is determined under what conditions there is an elasticity theory analogue of the Dykhne formula for the effective conductivity. The theoretical results are supported by known experiments and show improvement over the existing approach. The introduction of the theory with the variable percolation threshold paves the way for describing the magnetorheological properties of magnetoactive elastomers. A similar approach has been recently used for the description of magneto-dielectric and magnetic properties. KW - elastic properties KW - effective medium approximation KW - self-consistent KW - random heterogeneous medium KW - two-phase composite material KW - percolation threshold Y1 - 2020 U6 - https://doi.org/10.3390/ma13051243 VL - 13 IS - 5 SP - 1 EP - 19 PB - MPDI CY - Basel ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Zorinets, Denis A1 - Shamonin (Chamonine), Mikhail A1 - Kalita, Viktor M. T1 - Theoretical method for calculation of effective properties of composite materials with reconfigurable microstructure BT - Electric and magnetic phenomena JF - Physica A: Statistical Mechanics and its Applications N2 - We propose a theoretical approach for calculating effective electric and magnetic properties of composites, with field dependent restructuring of the filler. The theory combines the effective medium approximation, extended to a field-dependent (variable) percolation threshold, with an approximate treatment of the nonlinearity of material properties. Theoretical results are compared with experiments on magnetorheological elastomers, which in the context of investigated phenomena are often called magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of inclusions changes in an applied magnetic field. This reorganization of the microstructure leads to unconventionally large changes of electrical and magnetic properties. The obtained theoretical results describe observed phenomena in MAEs well. For the magnetodielectric effect, qualitative agreement between theory and experiment is demonstrated. In the case of magnetic permeability, quantitative agreement is achieved. The theoretical approach presented can be useful for the development of field-controlled smart materials and design of intelligent structures on their basis, because the field dependence of physical properties can be predicted. (C) 2019 Elsevier B.V. All rights reserved. KW - CONDUCTIVITY KW - EFFECTIVE RESPONSE KW - magnetoactive elastomers KW - PERCOLATION KW - PERMEABILITY Y1 - 2019 U6 - https://doi.org/10.1016/j.physa.2019.122467 VL - 535 IS - December PB - Elsevier ER - TY - JOUR A1 - Bodnaruk, Andrii V. A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Snarskii, Andrei A. A1 - Brunhuber, Alexander A1 - Shamonin (Chamonine), Mikhail T1 - Temperature blocking and magnetization of magnetoactive elastomers JF - Journal of Magnetism and Magnetic Materials N2 - The magnetization of a magnetoactive elastomer (MAE) with microparticles of soft magnetic carbonyl iron embedded in a highly elastic matrix has been studied. It is shown that at high temperatures its magnetization curve has the form of a specific hysteresis loop. This hysteresis is attributed to the influence of displacement of magnetized particles in the elastically soft elastomer matrix under the effect of magnetic forces, leading to the change of magnetic interaction between the particles. In this case, there is a maximum in the field dependence of the magnetic susceptibility, the occurrence of which has been associated with the competition between rearrangement of particles, when they are displaced in a magnetic field, and saturation of particles' magnetization. When the MAE is cooled below approximately 225 K, both the magnetic hysteresis and the maximum in the field dependence of the magnetic susceptibility disappear. When the MAE material is cooled below the solidification temperature of the elastomer matrix, the displacements of the magnetic particles during magnetization are blocked by the rigid matrix. The magnetization reversal of the MAE is reversible. This means that the shape of subsequent magnetization loops remains constant and the sample returns into the initial non-magnetized state after the magnetic field is turned off. KW - Hysteresis loop KW - Magnetization reversal KW - magnetoactive elastomer KW - Magnetorheological elastomers KW - MICROSTRUCTURE KW - Solidification Y1 - 2019 U6 - https://doi.org/10.1016/j.jmmm.2018.10.005 VL - 471 IS - February SP - 464 EP - 467 PB - Elsevier ER - TY - JOUR A1 - Bodnaruk, A1 - Andrii V., A1 - Brunhuber, Alexander A1 - Kalita, Viktor M. A1 - Kulyk, Mykola M. A1 - Kurzweil, Peter A1 - Snarskii, Andrei A. A1 - Lozenko, Albert F. A1 - Ryabchenko, Sergey M. A1 - Shamonin (Chamonine), Mikhail T1 - Magnetic anisotropy in magnetoactive elastomers, enabled by matrix elasticity JF - Polymer N2 - Polydimethylsiloxane based magnetoactive elastomers demonstrate above the melting transition range (e.g. at room temperature) an induced uniaxial magnetic anisotropy, which grows with increasing magnetic field. By freezing a material down to 150 K, displaced iron microparticles are immobilized, so that the magnetic anisotropy can be measured. Magnetic anisotropy “constant” is a consequence of particle displacements and a characteristic of the energy of internal deformations in the polymer matrix. The maximum anisotropy constant of the filling is at least one order of magnitude larger than the shear modulus of the pure elastomer (matrix). In a magnetic field, the gain in the rigidity of the composite material is attributed to the magnetomechanical coupling, which is in turn a source of anisotropy. The concept of effective magnetic field felt by the magnetization allows one to explain the magnetization curve at room temperature from low-temperature measurements. The results can be useful for developing vibration absorbers and isolators. KW - Experimental methodology KW - Internal deformation KW - magnetic properties KW - magnetoactive elastomer KW - Magnetomechanical coupling KW - magnetorheological elastomer Y1 - 2019 U6 - https://doi.org/10.1016/j.polymer.2018.12.027 VL - 162 IS - January SP - 63 EP - 72 PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Kalita, Viktor M. A1 - Shamonin (Chamonine), Mikhail T1 - Renormalization of the critical exponent for the shear modulus of magnetoactive elastomers JF - Scientific Reports N2 - It is shown that the critical exponent for the effective shear modulus of a composite medium where a compliant polymer matrix is filled with ferromagnetic particles may significantly depend on the external magnetic field. The physical consequence of this dependence is the critical behavior of the relative magnetorheological effect. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-22333-6 N1 - Corresponding author: Mikhail Shamonin VL - 8 SP - 1 EP - 8 PB - Nature ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium JF - Technical Physics N2 - A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated. KW - Magnetic Field KW - Permeability KW - Hysteresis Loop KW - Remanent Magnetization KW - Applied Magnetic Field Y1 - 2002 U6 - https://doi.org/10.1134/1.1435901 VL - 47 SP - 125 EP - 128 PB - Springer ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. A1 - Shamonin (Chamonine), Mikhail T1 - The effective properties of macroscopically nonuniform ferromagnetic composites: Theory and numerical experiment JF - Journal of Experimental and Theoretical Physics N2 - Various theoretical models (self-consistent field, local linearization, and percolation theory methods and an analytic solution of the linear problem for an ordered medium) for calculating the magnetostatic properties of two-phase composites containing one ferromagnetic phase were considered. The concentration and field dependences of the effective magnetic permeability were found. A method for determining the coercive force and remanent magnetization as functions of the ferromagnetic phase concentration was suggested. Numerical experiments were performed for composites with a periodic distribution of circular inclusions. The results were compared with the analytically calculated effective magnetic permeability. KW - Numerical Experiment KW - Remanent Magnetization KW - Field Dependence KW - Coercive Force KW - Magnetic Permeability Y1 - 2003 U6 - https://doi.org/10.1134/1.1545385 VL - 96 SP - 66 EP - 77 PB - Springer ER - TY - JOUR A1 - Shamonin (Chamonine), Mikhail A1 - Snarskii, Andrei A. A1 - Zhenirovskyy, M. I. T1 - Effective magnetic permeability of ferromagnetic composites. Theoretical description and comparison with experiment JF - NDT & E International N2 - Two analytical methods based on the so-called local linearization of magnetostatic properties of composite materials with ferromagnetic inclusions in a non-magnetic matrix are described. These methods are applied to the experimental data obtained in Gorkunov et al. [Russ. J. Nondestruct. Test. 3 (2001) 186]. A qualitative agreement is obtained for the concentration values reported in that paper and a quantitative agreement is achieved at slightly different value of concentration. The conclusions are supported by direct numerical modeling. KW - Material characterization KW - Ferromagnetic composites KW - Magnetostatic properties Y1 - 2004 U6 - https://doi.org/10.1016/j.ndteint.2003.08.001 VL - 37 IS - 1 SP - 35 EP - 40 PB - Elsevier ER - TY - JOUR A1 - Lukyanets, S. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Bakaev, V. V. T1 - Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach JF - NDT & E International N2 - A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed. KW - Magnetic methods KW - Flux leakage KW - Mathematical model KW - Defects Y1 - 2003 U6 - https://doi.org/10.1016/S0963-8695(02)00071-3 VL - 36 IS - 1 SP - 51 EP - 55 PB - Elsevier ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zhenirovskyy, M. I. T1 - Effective properties of macroscopically non-uniform ferromagnetic composite materials BT - Theory and numerical experiment JF - Zhurnal Eksperimental'noj i Teoreticheskoj Fiziki - Journal of Experimental and Theoretical Physics (JETP) Y1 - 2003 VL - 123 IS - 1 SP - 79 EP - 92 PB - Akademija Nauk SSSR CY - Moscow ER - TY - JOUR A1 - Lukyanets, S. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Bakaev, V. V. T1 - Calculation of magnetic leakage field from a surface defect in a linear ferromagnetic material: an analytical approach JF - NDT & E International N2 - A novel analytical approach for calculating the magnetic leakage field from surface defects is proposed and demonstrated for the case of a linear ferromagnetic material. The novelty of the theory is that it relates the distribution of induced magnetic charges to the surface shape. An excellent agreement between the analytical and numerical results is shown. The functional relations between different magnetic field components are discussed. KW - Magnetic methods KW - Flux leakage KW - Mathematical model KW - Defects Y1 - 2003 U6 - https://doi.org/10.1016/s0963-8695(02)00071-3 VL - 36 IS - 1 SP - 51 EP - 55 PB - Elsevier ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The permeability and remanent magnetization of a randomly inhomogeneous two-phase medium JF - Technical Physics N2 - A randomly inhomogeneous composite consisting of two, ferromagnetic and nonmagnetic (para-or diamagnetic), phases is considered. The dependence of the effective permeability of the composite on the concentration of the ferromagnetic phase and on the applied magnetic field is found for the case of the negligible hysteresis loop. When the hysteresis loop is appreciable, the remanent magnetization as a function of the ferromagnet concentration is calculated. Y1 - 2002 U6 - https://doi.org/10.1134/1.1435901 VL - 47 IS - 1 SP - 125 EP - 128 PB - Springer ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Zhenirovskyy, M. I. A1 - Trautner, Ralph T1 - Effect of disorder on the conductivity of two-phase strongly inhomogeneous highly filled composites JF - Theoretical and Mathematical Physics N2 - The effect of the “stir” of a structure (small deviations from strict periodicity) on effective conductivity is considered. For determinate and random deviations, concentration and field dependences of the effective conductivity are found. Numerical experiments with determinate deviations are carried out for the cases of linear (with respect to the field) inclusions embedded in both a linear and nonlinear matrix. The numerical results are compared with the effective conductivity calculated analytically. KW - Small Deviation KW - Numerical Experiment KW - Field Dependence KW - Effective Conductivity KW - Random Deviation Y1 - 2005 U6 - https://doi.org/10.1134/1.1854818 VL - 50 SP - 11 EP - 18 PB - Springer ER - TY - JOUR A1 - Bakaev, V. V. A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail T1 - The effective magnetic permeability of a two-phase fibred ferromagnetic composite JF - Technical Physics Y1 - 2001 U6 - https://doi.org/10.1134/1.1427995 VL - 46 IS - 12 SP - 1571 EP - 1574 PB - Springer ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel T1 - Effect of magnetic-field-induced restructuring on the elastic properties of magnetoactive elastomers JF - Journal of Magnetism and Magnetic Materials N2 - Composite materials where magnetic micrometer-sized particles are embedded into a compliant polymer matrix are known as magnetorheological (or magnetoactive) elastomers (MAEs). They are distinguished by huge variations in their physical properties, when in a magnetic field, which is commonly attributed to the restructuring of the filler. The process of the magnetic-field-induced restructuring in a magnetorheological elastomer is interpreted as progression towards percolation. Such a physical model was previously used to explain the dependence of the magnetic permeability and dielectric permittivity of MAEs on the magnetic field strength. Based on this hypothesis, the magnetorheological effect in MAEs is considered theoretically. The theoretical approach is built upon a self-consistent effective-medium theory for the elastic properties, extended to the variable (field dependent) percolation threshold. The proposed model allows one to describe the large variations (over several orders of magnitude) of the effective elastic moduli of these composite materials, known as the giant magnetorheological (MR) and field-stiffening effects. The existence of a giant magnetic Poisson effect is predicted. The relation of the proposed model to the existing theories of the MR effect in MAEs is discussed. The results can be useful for applications of MAEs in magnetic-field-controlled vibration dampers and isolators. Y1 - 2021 U6 - https://doi.org/10.1016/j.jmmm.2020.167392 IS - 517, January PB - Elsevier ER -