Faculty Publications

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Author: search.filters.author.Kattimani, S.C.

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    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). © 2017 Elsevier Ltd.
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    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. © 2018 Elsevier Ltd. All rights reserved.
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    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. © 2018 Author(s).
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    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. © 2018 Author(s).
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    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. © 2020 Author(s).
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    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. © 2020 Author(s).
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    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 [0°/45°/-45°/90°]s, bending stiff [0°/0°/30°/-30°]s, and torsion stiff [45°/-45°/-45°/45°]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. © 2020 Author(s).
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    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. © 2020 Author(s).
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    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
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    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