Faculty Publications

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Publications by NITK Faculty

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Author: search.filters.author.Kattimani, S.Subject: search.filters.subject.Time domain analysis

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    Vibration control of multiferroic fibrous composite plates using active constrained layer damping
    (Academic Press, 2018) Kattimani, S.; Ray, M.C.
    Geometrically nonlinear vibration control of fiber reinforced magneto-electro-elastic or multiferroic fibrous composite plates using active constrained layer damping treatment has been investigated. The piezoelectric (BaTiO3) fibers are embedded in the magnetostrictive (CoFe2O4) matrix forming magneto-electro-elastic or multiferroic smart composite. A three-dimensional finite element model of such fiber reinforced magneto-electro-elastic plates integrated with the active constrained layer damping patches is developed. Influence of electro-elastic, magneto-elastic and electromagnetic coupled fields on the vibration has been studied. The Golla–Hughes–McTavish method in time domain is employed for modeling a constrained viscoelastic layer of the active constrained layer damping treatment. The von Kármán type nonlinear strain-displacement relations are incorporated for developing a three-dimensional finite element model. Effect of fiber volume fraction, fiber orientation and boundary conditions on the control of geometrically nonlinear vibration of the fiber reinforced magneto-electro-elastic plates is investigated. The performance of the active constrained layer damping treatment due to the variation of piezoelectric fiber orientation angle in the 1–3 Piezoelectric constraining layer of the active constrained layer damping treatment has also been emphasized. © 2018 Elsevier Ltd
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    Vibration control of laminated composite cantilever beam operating in elevated thermal environments using fuzzy logic controller
    (SAGE Publications Inc., 2022) Akumalla, R.K.; Kallannavar, V.; Kattimani, S.
    In the present study, vibration control of laminated composite cantilever beam operating in the elevated thermal environment is achieved using combined experimental and numerical techniques. The impact hammer test is performed on the glass-epoxy cantilever beam at different temperatures. Experimentally recorded impact hammer force signals and piezoelectric accelerometer time-domain signals are processed through a system identification toolbox in MATLAB to obtain transfer functions of the plant models. A robust fuzzy logic controller is developed to accomplish the effective vibration control of a cantilever composite beam operating at different temperatures. The fuzzy logic controller with two inputs and one output is designed using the 20 if-then rules. The results are presented in both frequency and time domain, keeping the vibration attenuation of the fundamental frequency as the point of interest. The results indicate the proposed fuzzy logic control strategy can attenuate the vibrations of a cantilever composite beam for a wide temperature range. © The Author(s) 2022.
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    Effect of porosity on active damping of geometrically nonlinear vibrations of a functionally graded magneto-electro-elastic plate
    (China Ordnance Industry Corporation, 2022) Esayas, L.S.; Kattimani, S.
    This paper investigates the effect of porosity on active damping of geometrically nonlinear vibrations (GNLV) of the magneto-electro-elastic (MEE) functionally graded (FG) plates incorporated with active treatment constricted layer damping (ATCLD) patches. The perpendicularly/slanted reinforced 1–3 piezoelectric composite (1–3 PZC) constricting layer. The constricted viscoelastic layer of the ATCLD is modeled in the time-domain using Golla-Hughes-McTavish (GHM) technique. Different types of porosity distribution in the porous magneto-electro-elastic functionally graded PMEE-FG plate graded in the thickness direction. Considering the coupling effects among elasticity, electrical, and magnetic fields, a three-dimensional finite element (FE) model for the smart PMEE-FG plate is obtained by incorporating the theory of layer-wise shear deformation. The geometric nonlinearity adopts the von Kármán principle. The study presents the effects of a variant of a power-law index, porosity index, the material gradation, three types of porosity distribution, boundary conditions, and the piezoelectric fiber's orientation angle on the control of GNLV of the PMEE-FG plates. The results reveal that the FG substrate layers' porosity significantly impacts the nonlinear behavior and damping performance of the PMEE-FG plates. © 2021 China Ordnance Society