Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Kattimani, S.C.Subject: search.filters.subject.Coupled constitutive equations

Search Results

Now showing 1 - 8 of 8
  • No Thumbnail Available
    Item
    Static studies of stepped functionally graded magneto-electro-elastic beam subjected to different thermal loads
    (Elsevier Ltd, 2017) Mahesh, M.; Kattimani, S.C.
    In this article, a three dimensional finite element (FE) formulation for a multilayered magneto-electro-elastic (MEE) beam in thermal environment is presented. The equilibrium equations of the system are attained using the principle of total potential energy and linear coupled constitutive equations of MEE material. The corresponding FE equations are derived and the numerical evaluation of stepped functionally graded (SFG) MEE beam is carried out. The influence of various in-plane and through thickness temperature distributions on the direct quantities (displacements and potentials) and derived quantities (stresses, electric displacement and magnetic flux density), across the thickness of SFG-MEE cantilever beam is analyzed. In addition, an attempt has been made to investigate the effect of stacking sequence, thermo-magnetic and thermo-electric coupling on the direct quantities of the SFG-MEE beam. Further, a comparative study is made to evaluate the variations of displacements, potentials, electric displacements, magnetic flux density and stresses at different regions of the beam. It is expected that the results presented in this article may be useful in the design and analysis of MEE smart structures and sensor applications. © 2016 Elsevier Ltd
  • No Thumbnail Available
    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 Ltd
  • No Thumbnail Available
    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.
  • No Thumbnail Available
    Item
    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 Ltd
  • No Thumbnail Available
    Item
    Active damping of multiferroic composite plates using 1-3 piezoelectric composites
    (Institute of Physics Publishing michael.roberts@iop.org, 2017) Kattimani, S.C.
    A layer-wise shear deformation theory is used to analyze the smart damping of multiferroic composite or magneto-electro-elastic (MEE) plates. The intent of this analysis is to investigate the need for incorporating additional smart elements for controlling the vibrations of multiferroic composite plates. Active constrained layer damping (ACLD) treatment has been incorporated to alleviate the vibration of MEE plate. A layer of viscoelastic material is used as constrained layer for the ACLD treatment. The coupled constitutive equations of multiferroic (ferroelectric and ferromagnetic) composite materials along with the total potential energy principle are used to derive the finite element formulation for the overall multiferroic or MEE plate. Maxwell's electrostatic and electromagnetic relations are used to compute the electric and magnetic potential distribution. Influence of obliquely reinforced piezoelectric fibers in the piezoelectric layer of the ACLD treatment has also been investigated. In order to investigate the importance of using ACLD treatment for an active damping of multiferroic or MEE plate, an active control of MEE plate has also been analyzed by providing the control voltage directly to the piezoelectric layers of the MEE substrate plate without using the ACLD treatment. The present study suggests that for an optimal control of MEE plates, the smartness element such as the ACLD treatment is essentially required. © 2017 IOP Publishing Ltd.
  • No Thumbnail Available
    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.
  • No Thumbnail Available
    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 SAS
  • No Thumbnail Available
    Item
    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 Ltd