Faculty Publications
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Item Transverse stresses in antisymmetric angle ply sandwich plates - Analytical evaluation of refined higher order shear deformation theories(2010) Swaminathan, K.; Sangwai, G.R.In the present work two higher order computational models with 9 and 12 DOF already available in the literature for which analytical formulations and solutions for the stress analysis not yet reported are considered. In addition to these models, few higher order models and the first order model developed by other investigators are also considered for the evaluation. A simply supported plate subjected to sinusoidal transverse load with SS-2 boundary conditions is considered for the analysis. Solutions are obtained using Navier's technique. Transverse stresses are computed by post processing technique and the accuracy of models in predicting the stresses is evaluated. © (2010) Trans Tech Publications.Item Stress analysis of Antisymmetric angle ply sandwich plates- analytical evaluation of refined higher order shear deformation theories(CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2011) Swaminathan, K.; Sangwai, G.R.In this paper two refined higher order computational models with 9 DOF and 12 DOF are considered. Analytical formulation developed and solutions obtained for the first time using these models for the stress analysis of antisymmetric angle ply sandwich plate. In addition, higher order model proposed by Reddy and the first order model already reported in the literature are also considered for the evaluation. A simply supported plate with SS-2 boundary conditions is considered for the analysis. The equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier’s technique. In-plane stresses are computed using the three dimensional constitutive relationships and the transverse stresses by post processing technique. Extensive numerical results using all the models are compared with 3D elasticity solutions already available in the literature to decide the accuracy of model. After establishing accuracy of the solution method benchmark results and comparison of solutions are presented for multilayer sandwich plates. It is observed that ESL models with twelve DOF are accurate, efficient and simple. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item The effect of higher order model on the geometric nonlinear analysis of antisymmetric angle ply laminates(Smithers Rapra, 2016) Swaminathan, K.; Sangeetha, D.M.Geometric nonlinear analysis of simply supported antisymmetric angle-ply laminated composite plates are investigated based on first order and higher order displacement models with five degrees of freedom. Analytical formulations and solutions are developed based on Von-Karman nonlinear plate theory and Taylor's series expansion of displacement components. Equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE) and closed form solutions using Navier's Solution technique. A four layered square plate is considered for the present study. Parametric studies are performed on both the models to study the behaviour of displacements and stresses in laminated composite plates. Comparative studies are performed on both the models and the effect of geometric nonlinearity is discussed. © 2016 Smithers Information Ltd.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 LtdItem Performance study of jute-epoxy composites/sandwiches under normal ballistic impact(China Ordnance Society, 2020) Rajole, S.; Ravishankar, K.S.; Kulkarni, S.M.This study is undertaken to explore the use of natural fiber Jute-epoxy (JE), Jute-epoxy-rubber (JRE) sandwich composite for ballistic energy absorption. Energy absorbed and residual velocities for these composites are evaluated analytically and through Finite Element Analysis (FEA). FE analysis of JE plates is carried out for different thicknesses (3, 5, 10 and 15 mm). JE plates and JRE sandwiches having the same thickness (15 mm) are fabricated and tested to measure residual velocity and energy absorbed. The analytical results are found to agree well with the results of FE analysis with a maximum error of 9%. The study on JE composite plate reveals that thickness influences the energy absorption. Experimental and FE analysis study showed that JRE sandwiches have better energy absorption than JE plates. Energy absorption of a JRE sandwich is about 71% greater than JE plates. Damages obtained from FEA and testing are in good agreement. SEM analysis confirms composites failed by fiber rupture and fragmentation. © 2019 The AuthorsItem Free vibration analysis of A357 alloy reinforced with dual particle size silicon carbide metal matrix composite plates using finite element method(Polska Akademia Nauk, 2021) Avinash, A.; Mahesh, V.; Prabhu, R.T.; Gowdru Chandrashekarappa, M.G.C.; Bontha, S.In this work, the free vibration behaviour of A357 composite plate reinforced with dual particle size (DPS) (3 wt.% coarse + 3 wt.% fine, 4 wt.% coarse + 2 wt.% fine, and 2 wt.% coarse + 4 wt.% fine) SiC is evaluated using the finite element method. To this end, first-order shear deformation theory (FSDT) has been used. The equations of motion have been derived using Hamilton's principle and the solution has been obtained through condensation technique. A thorough parametric study was conducted to understand the effect of reinforcement size and weight fraction, boundary conditions, aspect ratio and length-to-width ratio of plate geometry on natural frequencies of A357/DPS-SiC composite plates. Results reveal significant influence of all the above variables on natural frequency of the composite plates. In all the cases, A357 composite plate reinforced with 4 wt.% coarse and 2 wt.% fine SiC particles displayed the highest natural frequency owing to its higher elastic and rigidity modulus. Further, the natural frequencies increase with decrease in aspect ratio of the plate geometry. Natural frequency also decreases with increase in the number of free edges. Lastly, increasing the length-to-width ratio drastically improves the natural frequency of the plates. © 2021 Polish Academy of Sciences. All rights reserved.Item 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. © 2022Item Thermal buckling and vibro-acoustic behaviour of functionally graded graphene polymer layered composites subjected to in-plane temperature variance(SAGE Publications Ltd, 2022) John, B.O.; Hassan, F.U.; George, N.; Chacko, T.; Bhagat, V.S.; Jeyaraj, J.; Kiran Kumar Reddy, R.The current study reports the thermal buckling, vibration and acoustic characteristics of functionally graded graphene polymer layer composite plates subjected to the in-plane temperature variance. The macroscopic properties of the composites are evaluated using the modified rule of mixtures to compute the layer-wise properties of an functionally graded graphene polymer layer composite plate. The critical buckling temperature is computed and compared for various functional gradings, boundary conditions and in-plane temperature variances. The in-plane temperature variance showed a major impact on the critical thermal buckling temperature and respective mode shapes. The vibro-acoustic behaviour of the functionally graded graphene polymer layer composite plate is investigated and documented keeping critical buckling temperature as a function. With an increase in thermal load and the nature of in-plane temperature variance, the vibro-acoustic results showed significant difference in velocity and acoustic response. For functionally graded graphene polymer layer composite plate with one free edge, the difference was statistically significant as indicated by an octave band plot. We conclude that the portion of the functionally graded graphene polymer layer composite plate that is subjected to the higher temperature in an in-plane temperature variance, as well as the nature of the boundary conditions may exacerbate the effect of in-plane temperature variance and are crucial in predicting vibro-acoustic characteristics. © IMechE 2022.Item 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 LtdItem Effect of radiofrequency coil and primary magnetic field on radiolucent composite plates(SAGE Publications Inc., 2023) Gawande, A.S.; Mukka Ramachanra, S.; kamyab, H.; Nguyen, N.-T.; Kattimani, S.Magnetic Resonance Imaging (MRI) systems need a material compatible with the imaging technique with lesser attenuation and provide accurate images without distortion. Carbon fibers are the best-suited materials for x-ray applications because of their radiolucent properties and reduced attenuation characteristics. However, carbon fiber produces images with distortion in the MRI system by absorbing electromagnetic energy because of its conductive nature. In the present study, five different fiber-reinforced radiolucent composite plates are analyzed to predict their suitability for a radio frequency coil and the effect of a primary magnetic field of 1.5 T and 3.0 T on mechanical responses. Simulation models are built to explore the impact of electromagnetic waves and birdcage coil configurations on composite material and quantify the temperature changes caused due to energy absorption. A multiphysics coupling simulation is being used to understand the effect of stacking sequence, ply orientation, and boundary conditions on the response of composite plates under an electro-magneto-mechanical environment. © The Author(s) 2022.