Browsing by Author "Kattimani, S.C."

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A 3D finite element static and free vibration analysis of magneto-electro-elastic beam
(Techno Press technop2@chollian.net, 2017) Mahesh, M.; Kattimani, S.C.
In this paper, free vibration and static response of magneto-electro-elastic (MEE) beams has been investigated. To this end, a 3D finite element formulation has been derived by minimization the total potential energy and linear constitutive equation. The coupling between elastic, electric and magnetic fields can have a significant influence on the stiffness and in turn on the static behaviour of MEE beam. Further, different Barium Titanate (BaTiO3) and Cobalt Ferric oxide (CoFe2O4) volume fractions results in indifferent coupled response. Therefore, through the numerical examples the influence of volume fractions and boundary conditions on the natural frequencies of MEE beam is illustrated. The study is extended to evaluate the static response of MEE beam under various forms of mechanical loading. It is seen from the numerical evaluation that the volume fractions, loading and boundary conditions have a significant effect on the structural behaviour of MEE structures. The observations made here may serve as benchmark solutions in the optimum design of MEE structures. © 2017 Techno-Press, Ltd.
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.
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.
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
Assessment of Vibrational Frequencies and Static Characteristics of Multilayered Skew Magneto-Electro-Elastic Plates: A Finite Element Study
(Springer, 2020) Kiran, M.C.; Kattimani, S.C.
This article presents a finite element (FE) model for free vibration and static analysis of layered skew magneto-electro-elastic (SMEE) plates by incorporating the shear deformation theory. The coupled constitutive equations of the MEE materials are used to derive the FE model accounting the effect of electro-elastic and magneto-elastic couplings. The displacement, electric potential and magnetic potential are considered as primary variables, while the stresses, electric displacement and magnetic induction are derived from the primary variables using constitutive equations. Influence of boundary conditions and material stacking sequences on the natural frequency, displacement and stresses of the SMEE plates has been investigated. Particular emphasis has been put on studying the effect of skew angles and aspect ratios on the natural frequencies, stresses, electric displacement and magnetic induction. The present study reveals that skew angle and aspect ratio significantly influence the structural behavior of SMEE plates. © 2018, Shiraz University.
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.
Dynamic performance of laminated composite plates with a circular hole
(American Institute of Physics Inc. subs@aip.org, 2020) Kallannavar, V.; Umatar, S.; Kattimani, S.C.
The present study deals with the free vibration analysis of laminated compo-site plates containing a circular hole or cut-out. The Finite Element (FE) analysis is used to study the influence of the type of material, size of the hole, aspect ratio of the plate and position of the circular hole on the natural frequency of the system. Three materials namely Glass-Epoxy, Boron-Epoxy and Graphite-Epoxy are considered for the simulation of plates containing a circular hole at the center for different boundary conditions. Influence of dimensions of rectangular plates on natural frequencies is presented by considering different aspect ratios under various boundary conditions. Distinct aspect ratios are achieved by varying length of the plate keeping width dimension constant. The study is also extended to understand the effect of position of the circular hole in the plate on modal behavior of the composite plate under different boundary conditions. Â© 2020 Author(s).
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.
Effect of temperature and moisture on free vibration characteristics of skew laminated hybrid composite and sandwich plates
(Elsevier Ltd, 2020) Kallannavar, V.; Kumaran, B.; Kattimani, S.C.
This paper is concerned with the effect of variation in temperature and moisture concentration on free vibration response of skew laminated hybrid composite and sandwich plates. The coupled thermo-elastic and hygro-elastic finite element model is formulated using the first-order shear deformation theory (FSDT). Uniform temperature and moisture concentration rise is considered for the analysis. Soft-core viscoelastic materials are considered for the sandwich plates and are modeled using the complex modulus approach. Linear strain-displacement relations are used to develop a mechanical stiffness matrix, and the initial stress stiffness matrix is generated using non-linear strain-displacement relations to represent the non-mechanical stiffness matrix. Numerical examples for the generated finite element model are presented and discussed comprehensively to understand the effect of temperature, moisture concentration, skew angle, length to width ratio, length to thickness ratio, and boundary conditions on the vibration response of the laminated hybrid composite and sandwich plates. Further investigation is devoted to studying the influence of temperature and moisture concentration-dependent material properties, stacking sequence, core to face sheet thickness ratio, and fiber orientation on vibration behavioral response of sandwich and hybrid composite plates. © 2020 Elsevier Ltd
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
Finite element modelling for mode-I fracture behaviour of CFRP
(American Institute of Physics Inc. subs@aip.org, 2018) Chethan, H.C.; Kattimani, S.C.; Murigendrappa, S.M.
Debonding is a major failure mechanism in Carbon Fiber Reinforced Polymer (CFRP) due to presence of many adhesion joins, in between many layers. In the current study a finite element simulation is carried out using Virtual Crack Closure Technique (VCCT) and Cohesive Zone Modelling (CZM) using Abaqus as analysis tool. A comparative study is performed in to order analyze convergence of results from CZM and VCCT. It was noted that CZM results matched well with published literature. The results from VCCT were also in good comparison with experimental data of published literature, but were seen to be overestimated. Parametric study is performed to evaluate the variation of input parameters like initial stiffness, element size, peak stress and energy release rate 'G'. From the numerical evaluation, it was noted that CZM simulation relies largely on element size and peak stress. Â© 2018 Author(s).
Flexural behavior of nanoclay filled glass fiber/epoxy polymer nanocomposites
(American Institute of Physics Inc. subs@aip.org, 2020) Bakshi, M.S.; Kattimani, S.C.
Flexural behavior of nanoparticle filled fiber reinforced polymer nanocomposite is very significant to the engineering applications. The halloysite nanotubes (HNTs) were effectively incorporated in epoxy resin and used to impregnate the unidirectional (UD) glass fiber. The flexural property was estimated by the three-point bend test as per ASTM standards, for samples containing varied loading of HNTs (0, 1, 2, 3 wt. %) in the nanocomposite. Differential scanning calorimetry (DSC) measurement was carried for room temperature and post cured samples. The effect of the addition of HNTs in shifting the glass transition temperature (Tg) of the nanocomposite was examined. Results show that maximum flexural strength and modulus values are obtained for the loading of 1 wt. % HNTs in the nanocomposite. Additionally, at this optimum loading, the Tg witnessed a notable improvement. DSC measurement of post cured samples revealed a 10.8% improvement in Tg at 1 wt. % HNT addition compared to its counter sample cured at room temperature. Scanning electron microscopy reveals a brittle failure for all the samples. Â© 2020 Author(s).
Free Vibration of Multilayered Magneto-Electro-Elastic Plates with Skewed Edges Using Layer wise Shear Deformation Theory
(Elsevier Ltd, 2018) Kiran, M.C.; Kattimani, S.C.
Present article discusses a novel method for the computation of non-dimensional eigen frequencies of a three dimensional multilayered magneto-electro-elastic plates (MEE) with skewed edges. A finite element (FE) model is formulated using a layerwise shear deformation theory (LSDT) and coupled constitutive equations. The transformation matrices are derived to transform local degrees of freedom into the global degrees of freedom for the nodes lying on the skew edges. Effect of different width to thickness ratios on the multilayered MEE plate with skewed edges is studied in detail. Particular attention has been paid to investigate the effect of various skew angles and stacking sequence on the non-dimensional eigen frequencies of multilayered MEE plate with simply supported boundary conditions. Â© 2018 Elsevier Ltd. All rights reserved.
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
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
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.
Hygrothermal response analysis of MEE beam embedded in adaptive wood through FE methods
(American Institute of Physics Inc. subs@aip.org, 2020) Mahesh, M.; Ravichandra, H.N.; Kattimani, S.C.; Nagaraja, C.V.
The present article evaluates coupled response of magneto-electro-hygrothermo-elastic (MEHTE) beam under framework of finite element methods. Through principle of total potential energy, equations of motions are derived. Solutions are obtained by incorporating the condensation procedure. Credibility of proposed formulation is validated by comparing the outcomes with previously published literature. Results reveal that with higher magnitude of hygrothermal loads, the static parameters of MEHTE beam significantly increases. Further, a comparative study between the thermal load alone and combined hygrothermal load reveals that the moisture effect plays a significant role in coupled response. The present work also attempts to evaluate the effects of various in-plane hygro-thermal loading profiles. Among the various hygrothermal loads considered, uniform hygrothermal load is found to have a predominant effect. Numerical examples are offered to assess individual effect of moisture as well. Â© 2020 Author(s).
Influence of Coupled Material Properties of BaTiO3 and CoFe2O4 on the Static Behavior of Thermo-Mechanically Loaded Magneto-Electro-Elastic Beam
(Elsevier Ltd, 2018) Mahesh, M.; Kattimani, S.C.
The present article deals with analyzing the influence of volume fraction (Vf) of Barium Titanate (BaTiO3) and Cobalt-Ferric oxide (CoFe2O4) and its corresponding coupled material properties on the static response of multiphase magneto-electro-elastic (MEE) cantilever beam. Using finite element (FE) methods, the variations of direct and derived quantities across the beam thickness are evaluated. The different volume fractions ranging from Vf =0.0 to Vf =1.0 are considered for analysis. The equilibrium equations are presented with the help of the total potential energy principle and coupled constitutive equations of MEE materials. The numerical results suggest that the displacement components vary accordingly with the volume fraction. In addition, it is found that the maximum electric potential is observed for Vf =0.2 due to pyro-effects, whereas maximum magnetic potential is obtained for Vf =0.0. The numerical study is extended to analyse the layered MEE beam. The influence of stacking sequence and different mechanical load forms on the direct quantities of the beam is evaluated. It is believed that for the precise design of any smart structure, the credibility of the material properties plays a significant role. Hence, in this regard an attempt has been made to understand the behavior of multiphase MEE beams with respect to different volume fractions of Barium titanate (BaTiO3) and Cobalt-Ferric oxide (CoFe2O4). Â© 2017 Elsevier Ltd.
Investigation of free vibration characteristics for skew multiphase magneto-electro-elastic plate
(American Institute of Physics Inc. subs@aip.org, 2018) Kiran, M.C.; Kattimani, S.C.
This article presents the investigation of skew multiphase magneto-electro-elastic (MMEE) plate to assess its free vibration characteristics. A finite element (FE) model is formulated considering the different couplings involved via coupled constitutive equations. The transformation matrices are derived to transform local degrees of freedom into the global degrees of freedom for the nodes lying on the skew edges. Effect of different volume fraction (Vf) on the free vibration behavior is explicitly studied. In addition, influence of width to thickness ratio, the aspect ratio, and the stacking arrangement on natural frequencies of skew multiphase MEE plate investigated. Particular attention has been paid to investigate the effect of skew angle on the non-dimensional Eigen frequencies of multiphase MEE plate with simply supported edges. Â© 2018 Author(s).
Modal analysis of laminated composite and sandwich plates using finite element method
(American Institute of Physics Inc. subs@aip.org, 2020) Kallannavar, V.; Kattimani, S.C.
The present study deals with an investigation of free vibration analysis of laminated composite and sandwich plates. The finite element model is developed in ANSYS Parametric Design Language (APDL) tool using shell elements for composite plates and solid shell elements for sandwich plates. The influence of material, fiber orientation, aspect ratio and boundary conditions on modal behavior of isotropic, laminated composite and sandwich plates are explored. Graphite- Epoxy was considered for the analysis of composite plates and aluminum 2024-T3 was considered for isotropic plate simulations. Sandwich structure was modeled by considering aluminum core and Graphite-Epoxy as face sheets. Quasi- isotropic [0Â°/45Â°/-45Â°/90Â°]s, bending stiff [0Â°/0Â°/30Â°/-30Â°]s, and torsion stiff [45Â°/-45Â°/-45Â°/45Â°]s fiber orientations are considered for the analysis. Block Lanczos mode extraction method was adopted to obtain natural frequency values. The simulation results indicated that the cantilever boundary condition is most suited for the applications where the operating frequency range is low. Â© 2020 Author(s).