Faculty Publications

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Author: search.filters.author.Jeyaraj, J.Subject: search.filters.subject.Shear deformation

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    Vibration analysis of a tapered laminated thick composite plate with ply drop-offs
    (Springer Verlag service@springer.de, 2015) Edwin Sudhagar, P.; Arumugam, A.; Vasudevan, R.; Jeyaraj, J.
    In this study, vibration characteristics of a tapered laminated thick composite plate have been investigated using finite element method by including the shear deformation and rotary inertia effects. The governing differential equations of motion of a tapered laminated thick composite plate are presented in the finite element formulation based on first-order shear deformation theory for three types of taper configurations. The effectiveness of the developed finite element formulation in identifying the various dynamic properties of a tapered laminated thick composite plate is demonstrated by comparing natural frequencies evaluated using the present FEM with those obtained from the experimental measurements and presented in the available literature. Various parametric studies are also performed to investigate the effect of taper configurations, aspect ratio, taper angle, angle ply orientation and boundary conditions on free and forced vibration responses of the structures. The comparison of the transverse free vibration mode shapes of the uniform and tapered composite plates under various boundary conditions is also presented. The forced vibration response of a composite plate is investigated to study the dynamic response of tapered composite plate under the harmonic force excitation in various tapered configurations. It is concluded that the dynamic properties of laminated thick composite plates could be tailored by dropping off the plies to yield various tapered composite plate. © 2015, Springer-Verlag Berlin Heidelberg.
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    Structural optimization of rotating tapered laminated thick composite plates with ply drop-offs
    (Springer Netherlands, 2017) Edwin Sudhagar, P.; Arumugam, A.; Vasudevan, V.; Jeyaraj, J.
    In this study, structural optimization of rotating tapered thick laminated composite plates with ply drop-offs has been investigated numerically. The governing differential equations of motion of the tapered composite plate have been presented including the energy associated with the inertia force, coriolis force, displacement dependent centrifugal force and initial stress resultants due to steady state rotation. Four noded quadrilateral finite element has been formulated based on the first order shear deformation theory. Finite element analysis results are validated with experimental results for natural frequencies of the tapered plate with various configurations. Various cases of optimization problems are formulated with different objective functions in terms of maximization of natural frequencies and damping factors (individually and combined) and solved using genetic algorithm in order to obtain optimal ply sequence and ply orientation. It is shown that the optimization problem with maximization of fundamental modal damping factor without rotating condition yields the optimal layout as 90° for all the layers in the plate. It is also observed that maximization of the fundamental modal damping factor yields identical optimal orientation for uniform and all the configurations of a tapered composite plate. © 2015, Springer Science+Business Media Dordrecht.
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    Analytical investigation on free vibration frequencies of polymer nano composite plate: Effect of graphene grading and non-uniform edge loading
    (Elsevier Ltd, 2020) Gunasekaran, V.; Jeyaraj, J.; Mailan Chinnapandi, L.B.M.
    An analytical investigation carried out on free vibration characteristics of functionally graded graphene reinforced nanocomposite (FG-GRC) plate under different non-uniform edge loads is presented. Graphene nano-platelets (GPLs) are homogeneously dispersed and graded by varying weight fraction through the thickness. An analytical method based on strain energy approach is adopted to estimate the buckling load. Natural frequencies of the FG-GRC plate are attained using analytical solutions derived based on Reddy's third-order shear deformation theorem (TDST). Results revealed that buckling and free vibration behavior of the plate is influenced by the GPLs dispersion pattern and weight fraction under non-uniform edge loads. It is also observed that buckling mode and the fundamental vibration mode of the plate under combined tensile-compression load is entirely different from the other non-uniform edge load cases. © 2020 Elsevier Ltd
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    Free vibration and stability of graphene platelet reinforced porous nano-composite cylindrical panel: Influence of grading, porosity and non-uniform edge loads
    (Elsevier Ltd, 2021) Twinkle, T.; Jeyaraj, J.
    Buckling and vibration characteristics of functionally graded(FG) porous(P), graphene platelet (GPL) reinforced cylindrical panel are presented. A multilayer model is considered for analysis with graphene and internal pores distribution varying in an uniformly or two different non-uniformly manner along the thickness. To evaluate the effective mechanical properties, extended rule of mixture together with modified Halpin-Tsai micromechanics model and mechanical properties of open-cell metal foams is used. Considering a higher order shear deformation theory, characteristics of the FG-P-GPL reinforced cylindrical panel under different edge loads such as uniform, triangular, trapezoidal and parabolic are investigated. The Hamilton's principle is used to formulate the governing partial differential equations and buckling and free vibration solutions are obtained by employing the Galerkins method. The influences of grading of GPL and internal pores, porosity coefficient on buckling and dynamic characteristics of functionally graded GPL reinforced porous cylindrical panel under uniform and non-uniform in-plane loads are presented. © 2020 Elsevier Ltd
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    A semi-analytical nonlocal elasticity model for static stability and vibration behaviour of agglomerated CNTs reinforced nano cylindrical panel under non-uniform edge loads
    (Elsevier Inc., 2022) Twinkle, C.M.; Jeyaraj, J.
    A semi analytical nonlocal elasticity model to analyze the effect of non-uniform edge loads on static stability and free vibration characteristics of agglomerated carbon nanotubes (CNTs) reinforced nano cylindrical panels are presented. Effective material properties of the agglomerated CNT reinforced composite are obtained using a two-parameter micro-mechanics model while Eringen's non-local theory is used to account the size effect. Sinusoidal shear deformation theory is adopted to analyze the buckling and vibration parameters using Galerkin's approach. The accuracy of the proposed model is presented first by comparing the results in the literature. Then a comprehensive study is carried out to analyze the influence of various degrees of agglomeration (complete, partial), nature of edge load, and non-local effects on the buckling and free vibration response of CNT reinforced nano cylindrical panel. The results revealed that non-local size effect leads to a reduction in stiffness and thus reduces buckling and dynamic characteristics. Moreover, it is observed that critical buckling load varies with type of in plane load and reduction in natural frequency is different for different in plane loading conditions. © 2021 Elsevier Inc.
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    An exact solution for vibro-acoustic response of smart sandwich panels with MEE composite Layer
    (Elsevier Ltd, 2022) Arunkumar, M.P.; Bhagat, V.S.; Geng, Q.; Li, Y.; Jeyaraj, J.
    To the best of our knowledge, this is the first endeavor to provide an exact solution for a vibro-acoustic response of Magneto-electro-elastic (MEE) composite plate and sandwich panels with MEE facings. The governing equation of motion is developed using Hamilton's principle considering the third-order shear deformation theory to account for transverse shear. Based on boundary conditions and the Maxwell equation, the variation of electric and magnetic potentials are adopted along the thickness of the MEE composite layer. Analysis of the vibro-acoustic response of sandwich panels which are extensively used in aerospace structures such as cellular, trapezoidal, triangular, and honeycomb are presented. Influences of electric and magnetic potential on the vibro-acoustic response are also presented for the different types of truss core and honeycomb core sandwich panels. © 2022
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    An exact solution for vibro-acoustic response of MEE composite plate
    (Elsevier Ltd, 2022) Arunkumar, M.P.; Bhagat, V.S.; Swetha, S.; Geng, Q.; Jeyaraj, J.; Li, Y.
    To the best of our knowledge, this is the first endeavor to present an exact solution to predict vibro-acoustic characteristics of Magneto-electro-elastic (MEE) composite plate. The transverse and in-plane fields are considered based on thin-plate conditions. The variation of electric and magnetic potentials is determined according to electromagnetic boundary conditions and the Maxwell equation. The stress resultants and mass inertias are used in Hamilton's principle to generate the governing equation. Here the mathematical formulation is developed using third-order shear deformation theory. Also in this work, the dynamic displacement responses are provided by finding five undetermined mode coefficients relevant to u, v, w, ϕx, and ϕy to predict forced vibration response. The forced vibration response obtained based on the developed governing equation is used to calculate the acoustic characteristics using the Rayleigh integral. The effect of magnetic and electric potential is shown in the acoustic responses. From the results, it is understood that the acoustic responses are highly influenced by the applied magnetic and electric potential. The radiation efficiency of the MEE plate did not show any variations in the lower frequency and it shows the variation near the resonant frequencies on the application of electric and magnetic potential. © 2022 Elsevier Ltd
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    Nonlinear flutter of 2D variable stiffness curvilinear fibers composite laminates by a higher-order shear flexible beam theory with Poisson's effect
    (Elsevier Ltd, 2022) Manickam, G.; Vasudevan, V.; Gunasekaran, V.; Jeyaraj, J.; Mohamed, H.
    In this work, the nonlinear supersonic panel flutter characteristics of two-dimensional variable stiffness curvilinear fibres based laminated composite panels are studied using a higher-order shear flexible theory represented by sine function coupled with first-order approximation leading to quasi-aerodynamic theory. The structural formation takes care of geometric nonlinearity with von Karman's assumptions. The beam constitutive equation is modified for the laminated beam with general lay-up by accounting for Poisson's effect. The nonlinear dynamic equilibrium equations developed by Lagrangian equations of motion are solved using finite element approach in conjunction with the direct iterative solution procedure. For limit cycle oscillation, critical dynamic pressure is predicted iteratively through eigenvalue analysis, thereby identifying the first coalescence of vibrational modes. Also, the flutter behavior of two-dimensional panel under static differential pressure is investigated considering nonlinear static equilibrium position of panel obtained by Newton-Raphson's iterative approach and then followed by modes coalescence approach. These solution procedures are tested against the results in literature. A thorough numerical investigation is done to show the effect of the curvilinear fiber path orientation, limited cycle amplitude, static differential pressure, panel thickness, panel end condition flexibilities and thermal environment on the nonlinear supersonic panel flutter of two-dimensional variable stiffness laminated panels. © 2022