Faculty Publications
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Item Geometrically nonlinear vibration analysis of multiferroic composite plates and shells(Elsevier Ltd, 2017) Kattimani, S.C.In this article, a layerwise shear deformation theory is incorporated for geometrically nonlinear vibration (GNV) analysis of multiferroic composite plates and doubly curved shells. The coupled constitutive equations involving ferroelastic, ferroelectric and ferromagnetic properties of multiferroic composite materials along with the total potential energy principle are utilized to derive the finite element formulation for the multiferroic or magneto-electro-elastic (MEE) plates/shells. The electric and the magnetic potentials are assumed to vary linearly in the transverse direction. The electric and magnetic potential distribution in the plate/shell is computed by using the Maxwell's electromagnetic relations. The significance of geometric nonlinearity has been considered using the von Kármán nonlinear strain-displacement relations. Importance of curvature aspect ratio, curvature ratio and the thickness aspect ratio on the nonlinear frequency ratios of the multiferroic/MEE doubly curved shells has been investigated. The backbone curves for multiferroic plates and shells have been studied by considering various aspect ratios. Impact of layer stacking sequence, boundary conditions and coupled fields on the central deflection and nonlinear frequency ratio of the multiferroic plates and shells have been investigated. © 2016 Elsevier LtdItem A finite element based assessment of static behavior of multiphase magneto-electro-elastic beams under different thermal loading(Techno-Press, 2017) Mahesh, M.; Kattimani, S.C.In this article, static analysis of a magneto-electro-elastic (MEE) beam subjected to various thermal loading and boundary conditions has been investigated. Influence of pyroeffects (pyroelectric and pyromagnetic) on the direct quantities (displacements and the potentials) of the MEE beam under different boundary conditions is studied. The finite element (FE) formulation of the MEE beam is developed using the total potential energy principle and the constitutive equations of the MEE material taking into account the coupling between elastic, electric, magnetic and thermal properties. Using the Maxwell electrostatic and electromagnetic relations, variation of stresses, displacements, electric and magnetic potentials along the length of the MEE beam are investigated. Effect of volume fractions, aspect ratio and boundary conditions on the direct quantities in thermal environment has been determined. The present investigation may be useful in design and analysis of magnetoelectroelastic smart structures and sensor applications. © 2017 Techno-Press, Ltd.Item Static behavior of thermally loaded multilayered Magneto-Electro-Elastic beam(Techno-Press, 2017) Mahesh, M.; Kattimani, S.C.The present article examines the static response of multilayered magneto-electro-elastic (MEE) beam in thermal environment through finite element (FE) methods. On the basis of the minimum total potential energy principle and the coupled constitutive equations of MEE material, the FE equilibrium equations of cantilever MEE beam is derived. Maxwell's equations are considered to establish the relation between electric field and electric potential; magnetic field and magnetic potential. A simple condensation approach is employed to solve the global FE equilibrium equations. Further, numerical evaluations are made to examine the influence of different in-plane and through-thickness temperature distributions on the multiphysics response of MEE beam. A parametric study is performed to evaluate the effect of stacking sequence and different temperature profiles on the direct and derived quantities of MEE beam. It is believed that the results presented in this article serve as a benchmark for accurate design and analysis of the MEE smart structures in thermal applications. © Copyright 2017 Techno-Press, Ltd.Item Static analysis of stepped functionally graded magneto-electro-elastic plates in thermal environment: A finite element study(Elsevier Ltd, 2017) Mahesh, M.; Kattimani, S.C.In this article, a finite element (FE) formulation accounting for multiphysics response of multilayered magneto-electro-elastic (MEE) plates in the thermal environment has been presented. The equilibrium equations of motion are attained using the principle of total potential energy and coupled constitutive relations of MEE material. Maxwell's equation of electrostatics and magnetostatics are used to model the electric and magnetic behavior. The influence of various through thickness temperature distributions on the static parameters of stepped functionally graded magneto-electro-elastic (SFG-MEE) plates is investigated. Further, an extra attention has been devoted to evaluate the effect of product properties (pyroelectric and pyromagnetic coupling), boundary conditions and aspect ratio on the direct (displacements, electric potential and magnetic potential) and derived quantities (stresses, electric displacement, and magnetic flux density) of the SFG-MEE plate. A comparative study is also carried out to analyse the effect of stacking sequence, boundary conditions, pyroeffects, length-to-width ratio and aspect ratios of the SFG-MEE plate. The credibility of the proposed FE model is verified with the results available in the literature. It is expected that the findings in this article may be useful for accurate design and analysis of MEE structures under the thermal environment. © 2017 Elsevier LtdItem Hygrothermal analysis of magneto-electro-elastic plate using 3D finite element analysis(Elsevier Ltd, 2017) Mahesh, M.; Kattimani, S.C.In this article, the static response of magneto-electro-elastic (MEE) plate subjected to hygrothermal loads is investigated using the finite element (FE) method. A FE formulation is derived using the principle of total potential energy and linear coupled constitutive equations of MEE materials by taking into account the thermal and hygroscopic field effects. A uniform temperature rise and moisture concentration rise has been considered. The variations of static parameters are estimated along the MEE plate length by considering the temperature and moisture dependant elastic stiffness coefficients. The coupled FE equilibrium equations in terms of displacements, electric and magnetic potentials are solved directly using condensation procedure. Numerical examples of the FE results are presented and discussed in detail to understand the significant effects of hygrothermal loading, temperature and moisture dependent material properties, boundary conditions and aspect ratio on the direct (displacements, electric potential and magnetic potential) and derived quantities (stresses, electric displacement and magnetic flux density) of MEE plate. © 2017 Elsevier LtdItem Buckling characteristics and static studies of multilayered magneto-electro-elastic plate(Techno-Press, 2017) Kiran, M.C.; Kattimani, S.C.This article deals with the buckling behaviour of multilayered magneto-electro-elastic (MEE) plate subjected to uniaxial and biaxial compressive (in-plane) loads. The constitutive equations of MEE material are used to derive a finite element (FE) formulation involving the coupling between electric, magnetic and elastic fields. The displacement field corresponding to first order shear deformation theory (FSDT) has been employed. The in-plane stress distribution within the MEE plate existing due to the enacted force is considered to be equivalent to the applied in-plane compressive load in the pre-buckling range. The same stress distribution is used to derive the potential energy functional. The non-dimensional critical buckling load is accomplished from the solution of allied linear eigenvalue problem. Influence of stacking sequence, span to thickness ratio, aspect ratio, load factor and boundary condition on critical buckling load and their corresponding mode shape is investigated. In addition, static deflection of MEE plate under the sinusoidal and the uniformly distributed load has been studied for different stacking sequences and boundary conditions. © © 2017 Techno-Press, Ltd.Item Hygrothermal coupling analysis of magneto-electroelastic beams using finite element methods(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2018) Mahesh, M.; Kattimani, S.C.; Joladarashi, S.In this article, the finite element (FE) method has been used to assess the coupled static behavior of hygro-thermo-magneto-electroelastic (HTMEE) beam. Influence of externally applied hygrothermal loads on the direct (displacements, electric and magnetic potentials) and derived quantities (stresses, electric displacement and magnetic flux densities) of HTMEE beam have been studied in detail. The principle of total potential energy and the coupled constitutive equations of HTMEE material are used for the FE formulation. A generalized condensation technique is adopted to solve the global FE equations of motion. Numerical examples are discussed to examine the effect of hygrothermal loads and distinct effect of moisture concentration on the behavior of the beam. Particular emphasis has been placed to analyze the influence of temperature and moisture dependent elastic stiffness coe?cients associated with empirical constants. Considering the independent effect of temperature and moisture on the coupled static responses, the most significant combination of the empirical constants corresponding to temperature dependency and moisture dependency are explored. Extensive computational examples are considered to examine the significant effect of boundary conditions, temperature gradient, moisture concentration gradient and empirical constants on the static behavior of HTMEE beam. It is observed that the static behavior of HTMEE beam is significantly influenced by the hygrothermal loads and empirical constants. The results presented in this article would serve as a benchmark results in design and analysis of HTMEE structures for sensors and actuators applications. © 2018 Taylor & Francis.Item Assessment of porosity influence on vibration and static behaviour of functionally graded magneto-electro-elastic plate: A finite element study(Elsevier Ltd, 2018) Kiran, M.C.; Kattimani, S.C.In this paper, the free vibration characteristics and the static behaviour of porous functionally graded magneto-electro-elastic (FGMEE) plate is investigated using finite element method. The porosities arise due to the maladies in the fabrication processes and such porosities or micro-voids are accounted using modified power law. Influence of different porosity distributions on the behaviour of PFGMEE plate are considered in this study. The through thickness variation of material properties is achieved to obtain a functionally graded MEE plate. The coupled constitutive equations along with the principle of virtual work are used to develop a FE model for FGMEE plates. Influence of various porosity distributions on the structural behaviour of the plate is thoroughly investigated. The effect of porosity volume and material gradient index on the free vibration and static behaviour is explicitly studied. This study also includes the evaluation of the effect of geometrical parameters such as thickness ratio, aspect ratio, and boundary condition on the structural characteristics of porous FGMEE plate. © 2018 Elsevier Masson SASItem Finite element evaluation of free vibration characteristics of magneto-electro-elastic rectangular plates in hygrothermal environment using higher-order shear deformation theory(Elsevier Ltd, 2018) Mahesh, M.; Kattimani, S.C.In this article, the effect of hygrothermal environment on the free vibration characteristics of magneto-electro-elastic (MEE) plates has been studied using finite element method. To this end, higher order shear deformation theory (HSDT) has been employed to assess the displacement fields. Further, using Hamilton's principle and linear coupled constitutive equations of MEE material, the final equilibrium equations for free vibration behaviour of MEE plate in hygrothermal environment has been derived. A special attention has been paid to evaluate the effect of temperature and moisture dependent elastic coefficients on the natural frequencies. The results reveal that the external temperature and moisture fields predominantly affect the stiffness of the plate and hence alter the free vibration characteristics drastically. It is believed that the results presented in this study are useful for the precise design of sensors and actuators in hygrothermal environment. © 2018 Elsevier LtdItem Effect of BaTiO3/CoFe2O4 micro-topological textures on the coupled static behaviour of magneto-electro-thermo-elastic beams in different thermal environment(Institute of Physics Publishing helen.craven@iop.org, 2018) Mahesh, M.; Kattimani, S.C.; Loja, M.A.R.; Mahesh, V.The use of composite materials with multifunctional capabilities is an increasing requirement for structures or components where the sensory function is accompanied by the diagnosis and the actuation functions, such as autonomic, adaptive or self-sustaining systems. In this context, the present study aims to characterize the coupled response of magneto-electro-thermo-elastic (METE) beams made from Barium Titanate (BaTiO3) and Cobalt Ferric Oxide (CoFe2O4) composite having various micro-topological textures, as well as their static response when submitted to different temperature distribution profiles. To this purpose, a three-dimensional finite element accounting for the coupling between the multiple physical fields in presence, is developed and implemented. The spatial heterogeneous BaTiO3/CoFe2O4 microstructure is also assessed by considering typical Body Centered Cubic (BCC), Face Centered Cubic (FCC) and Simple Cubic (SC) spatial packing arrangements. A special attention is paid to the influence of these micro-topological structures on the pyroeffects and its contribution towards the direct and derived quantities of the METE beam. The results obtained, suggest that the composite heterogeneous microstructure have a relevant influence on the static response of the METE beam in thermal environment. © 2018 IOP Publishing Ltd.