Browsing by Author "Swaminathan, K."

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A novel EFG meshless-ANN approach for static analysis of FGM plates based on the higher-order theory
(Taylor and Francis Ltd., 2024) K P, A.; Swaminathan, K.; Indu, N.; H, S.
An Element Free Galerkin (EFG) meshless formulation and solutions using higher order shear deformation theory with nine degrees of freedom for the static analysis of Functionally Graded Material (FGM) plates are provided. This technique estimates the shape function using Moving Least Squares (MLS) method. The proposed method is validated by comparing the present findings with those in the literature. A novel Artificial Neural Network (ANN) model is developed to forecast the deflection of FGM plates within less computational time. Detailed parametric and convergent studies reveal that the proposed EFG solution and the ANN technique are more efficient than their conventional counterparts. The validation and comparison of the generated results in the present investigation with the other analysis methods revealed that the EFG method and ANN model give more accurate results than the FEM and other meshless methods. The current EFG-ANN model reduces computing time by 99.94% when compared to the EFG approach. Also, the accuracy is enhanced using the EFG approach with HSDT9 for the FGM plate. © 2023 Taylor & Francis Group, LLC.
An Element-Free Galerkin (EFG) Meshless Solution for Static Analysis of FGM Plates Resting on Elastic Foundation
(Springer Science and Business Media Deutschland GmbH, 2024) Indu, N.; K P, K.P.; Swaminathan, K.
An element free Galerkin (EFG) meshless solution method is presented in this paper to illustrate the bending response of FGM plates resting on Winklerâ€“Pasternak elastic foundations. A power law distribution is used to govern the gradation of material properties through the plate thickness. To check the validity of the theory and formulations, the obtained results are compared with the previous results. Comparison studies reveal that the results of the proposed solution method is more accurate and yield faster results than other methods. Parametric studies are performed to show the influences of elastic foundation coefficients and power law index on the deflection of FGM plates. Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
Analytical formulations and solutions to the static analysis of simply supported anti-symmetric angle-ply composite and sandwich plates hitherto not reported in the literature based on a higher-order refined theory already reported in the literature are presented. The theoretical model presented herein incorporates laminate deformations, which account for the effect of transverse shear deformation and a non-linear variation of in-plane displacements with respect to the thickness coordinate. The transverse displacement is assumed to be constant throughout the thickness. The equations of equilibrium are obtained using principle of minimum potential energy. Solutions are obtained in closed form using Navier's technique by solving the boundary value problem. Accuracy of the theoretical formulations and the solution method is first ascertained by comparing the results with that already reported in the literature. After establishing the accuracy of the solutions, numerical results with real properties are presented for the multilayer antisymmetric angle-ply composite and sandwich plates, which will serve as a benchmark for future investigations. © 2003 Elsevier Ltd. All rights reserved.
(Analytical solutions using a higher-order refined theory for the static analysis of antisymmetric angle-ply composite and sandwich plates) Swaminathan, K.; Ragounadin, D.
2004
Analytical Solutions for the Thermo-Elastic Analysis of FGM Plates Using Higher Order Refined Theories
(National Institute of Technology Karnataka, Surathkal, 2017) D. M, Sangeetha; Swaminathan, K.
Analytical formulations and solutions are presented for the thermo-elastic analysis of Functionally Graded Material (FGM) plates based on a set of higher order refined shear deformation theories. The displacement components in these computational models are based on Taylor’s series expansions, which incorporates parabolic variation of transverse strains across the plate thickness. The displacement model with twelve degrees of freedom considers the effects of both transverse shear and normal strain/stress while the other model with nine degrees of freedom includes only the effect of transverse shear deformation. Besides these, a higher order model and a first order model with five degrees of freedom that are developed by other investigators and are reported in the literature are also used in the present investigation for evaluation purposes. A simply supported FGM plate subjected to thermal load is considered throughout as a test problem. The material properties are mathematically modeled based on power law function. The temperature is assumed to vary nonlinearly and obey one-dimensional steady state heat conduction equation throughout the plate thickness while in-plane is sinusoidal. Along with this constant and linearly varying temperatures are also considered in the study. The equations of equilibrium are derived using the Principle of Minimum Potential Energy (PMPE) and closed form solutions are obtained using Navier’s solution technique. Firstly, numerical results obtained using various displacement models are compared with the three-dimensional elasticity solutions available in the literature inorder to establish the accuracy of higher order models considered in the study. After establishing the accuracy of the solution method benchmark results and comparison of solutions are presented for Monel/Zirconia, Titanium-Alloy/Zirconia and Aluminium/Alumina FGM plate by varying edge ratio, slenderness ratio and power law parameter. Numerical and graphical results are presented for in-plane, transverse displacements and stresses for all the models by considering different temperature profiles.
Analytical solutions using a higher order refined computational model with 12 degrees of freedom for the free vibration analysis of antisymmetric angle-ply plates
(2008) Swaminathan, K.; Patil, S.S.
Analytical formulations and solutions to the natural frequency analysis of simply supported antisymmetric angle-ply composite and sandwich plates hitherto not reported in the literature based on a higher order refined computational model with 12 degrees of freedom already reported in the literature are presented. The theoretical model presented herein incorporates laminate deformations which account for the effects of transverse shear deformation, transverse normal strain/stress and a nonlinear variation of in-plane displacements with respect to the thickness coordinate thus modelling the warping of transverse cross sections more accurately and eliminating the need for shear correction coefficients. In addition, another higher order computational model with five degrees of freedom already available in the literature is also considered for comparison. The equations of motion are obtained using Hamilton's principle. Solutions are obtained in closed-form using Navier's technique by solving the eigenvalue equation. Plates with varying slenderness ratios, number of layers, degrees of anisotropy, edge ratios and thickness of core to thickness of face sheet ratios are considered for analysis. Numerical results with real properties using above two computational models are presented and compared for the free vibration analysis of multilayer antisymmetric angle-ply composite and sandwich plates, which will serve as a benchmark for future investigations. © 2007 Elsevier Ltd. All rights reserved.
Analytical solutions using a higher-order refined theory for the static analysis of functionally graded material plates
(2013) Swaminathan, K.; Naveenkumar, D.T.
Analytical formulations and solutions to the static analysis of simply supported Functionally Graded Material (FGM) plates hitherto not reported in the literature based on a higherorder refined shear deformation theory with nine degrees-of-freedom already reported in the literature are presented. This computational model incorporates the plate deformations which account for the effect of transverse shear deformation. The transverse displacement is assumed to be constant throughout the thickness. In addition, another higher order theory with five degrees-offreedom and the first order theory already reported in the literature are also considered for comparison. The governing equations of equilibrium using all the computational models are derived using the Principle of Minimum Potential Energy (PMPE) and the analytical solutions are obtained in closed-form using Navier's solution technique. A simply supported plate with SS-1 boundary conditions subjected to transverse loading is considered for all the problems under investigation. The varying parameters considered are the side-to-thickness ratio, power law function, edge ratio and the degree of anisotropy. Correctness of the formulation and the solution method is first established and then extensive numerical results using all the models are presented which will serve as a bench mark for future investigations. � (2013) Trans Tech Publications, Switzerland.
Analytical solutions using a higher-order refined theory for the static analysis of functionally graded material plates
(2013) Swaminathan, K.; Naveenkumar, D.T.
Analytical formulations and solutions to the static analysis of simply supported Functionally Graded Material (FGM) plates hitherto not reported in the literature based on a higherorder refined shear deformation theory with nine degrees-of-freedom already reported in the literature are presented. This computational model incorporates the plate deformations which account for the effect of transverse shear deformation. The transverse displacement is assumed to be constant throughout the thickness. In addition, another higher order theory with five degrees-offreedom and the first order theory already reported in the literature are also considered for comparison. The governing equations of equilibrium using all the computational models are derived using the Principle of Minimum Potential Energy (PMPE) and the analytical solutions are obtained in closed-form using Navier's solution technique. A simply supported plate with SS-1 boundary conditions subjected to transverse loading is considered for all the problems under investigation. The varying parameters considered are the side-to-thickness ratio, power law function, edge ratio and the degree of anisotropy. Correctness of the formulation and the solution method is first established and then extensive numerical results using all the models are presented which will serve as a bench mark for future investigations. Â© (2013) Trans Tech Publications, Switzerland.
Bending of sandwich plates with anti-symmetric angle-ply face sheets - Analytical evaluation of higher order refined computational models
(2006) Swaminathan, K.; Patil, S.S.; Nataraja, M.S.; Mahabaleswara, K.S.
The aim of the present study is to assess the accuracy of the few computational models based on various shear deformation theories in predicting the bending behaviour of sandwich plates with anti-symmetric angle-ply face sheets under static loading. Five two-dimensional models available in the literature are used for the present evaluation. The performance of the various models is evaluated on a simply supported laminated plate under sinusoidal loading. The equations of equilibrium are derived using the principle of minimum potential energy (PMPE). Analytical solution method using double Fourier series approach is used in conjunction with the admissible boundary conditions. The accuracy of each model is established by comparing the results of composite plates with the exact solutions already available in the literature. After establishing the correctness of the theoretical formulations and the solution method, benchmark results for transverse displacement, in-plane stresses, moment and shear stress resultants are presented for the multilayer sandwich plates. © 2006 Elsevier Ltd. All rights reserved.
Buckling analysis of functionally graded materials by dynamic approach
(Elsevier Ltd, 2020) Swaminathan, K.; Hirannaiah, H.; Rajanna, T.
Laminated composites exhibit difference in the mechanical properties at the interface between two materials resulting in stress concentration. This may lead to damages in the form of delamination, matrix cracking and adhesive bond separation. Functionally Graded Materials (FGM) are formed by gradual variation of two or more material over a particular volume, thereby overcomes these issues. Buckling problems of FGM plates are usually solved by static approach. In some cases, particularly non-uniform loading and geometric discontinuity, the stress concentration usually occurs. In such cases, the solution to the buckling problem by dynamic approach is most suitable. In the dynamic approach, the natural frequencies are calculated by applying in-plane loads. As the intensity of the in-plane load increases, the frequency of the material decreases and finally becomes zero at the onset of buckling. The load at which the natural frequency becomes zero that load is called a buckling load. In this investigation, the vibration and buckling characteristics of FGM panels subjected to uniaxial and biaxial loading conditions have been studied by using the finite element method (F.E.M). In the Finite element (FE) formulation, the effective material properties of FGM plates are assumed to vary in the thickness direction according to the power-law distribution of volume fraction of the constituents. The plate is modelled by using 8-noded serendipity element by incorporating the effect of transverse shear deformation and rotary inertia. The effect of different parameters such as volume fraction index (n), the thickness of the panel (h) and boundary condition of the plate are considered to study the buckling behaviour of the FGM plate under uniaxial loading conditions. Â© 2020 Elsevier Ltd. All rights reserved.
Buckling Response of Functionally Graded Material Plates with Cutouts Subjected to Linearly Varying Loads
(Springer Science and Business Media Deutschland GmbH, 2022) Swaminathan, K.; Hirannaiah, H.; Rajanna, T.
In most of the studies, the buckling problems are solved analytically based on the assumption that the plates are subjected to only uniform in-plane edge loads without any damages, in spite of the fact that, the real structural components are subjected to various kinds of non-uniform edge loads along with geometrical discontinuous. The current study provides numerical solutions for buckling problems of functionally graded material plates with and without circular cutouts subjected to linearly varying edge loads by using the finite element package (ABAQUS). The effective material properties are found along the thickness using the homogenization technique involving power law function. In the FE modelling, the plate is modelled by using eight noded elements (S8R5) with five degrees of freedom at each node. The influence of various parameters such as size of the cutout and its position, volume fraction index and type of loads are considered to investigate the effect of each parameter on the buckling phenomenon. Â© 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Computational model for the transverse stress analysis of FGM plates - An assessment
(2013) Swaminathan, K.; Naveenkumar, D.T.
This paper presents the complete theoretical formulation and the analytical solutions for stress analysis of functionally graded material (FGM) plates using First-order Shear Deformation Theory (FSDT). The material properties are assumed to be isotropic along the plane of the plate and vary through the thickness according to the power law function. The governing equations of equilibrium are derived using Principle of Minimum Potential Energy (PMPE) and the analytical solutions are obtained in closed-form using Navier's solution technique. The effect of variation of side-to-thickness ratio, modulus of elasticity ratio, edge ratio and the power law function on the behaviour of the plate is studied. Numerical results are presented for the transverse displacement, the in-plane and the transverse stresses. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.
Effect of initial stresses on vibration behavior of functionally graded materials
(Elsevier Ltd, 2020) Swaminathan, K.; Hirannaiah, H.; Rajanna, T.
Functionally Graded Materials (FGM) is the result of continuous gradation of two or more constituent materials over a certain volume. This type of material overcomes many problems, particularly delamination, cracking and damages which are very frequently found in laminated composite materials. The FGMs are commonly found in space structures, and these structural elements are subjected to various kinds of loadings during its service period, in which in-plane loading is the one which significantly affects the vibration characteristics of the structural elements. In this investigation, the effect of tensile and compressive stresses on vibration characteristics of FG panels has been studied by using finite element technique (FE). For mathematical modelling Poisson's ratio is assumed constant and Young's modulus of elasticity is assumed to vary according to the power-law distribution of volume fraction of the constituents. The plate is modelled by using 8-noded isoparametric element by considering the effect of transverse shear deformation and rotary inertia. The effect of different factors such as volume fraction index, the thickness of the panel, boundary condition and tensile as well as compressive edge loads are considered to study the vibration behaviour of the FGM plate under tensile and compressive uniaxial edge loads. Â© 2020 Elsevier Ltd. All rights reserved.
Effect of Porosity Distribution on Vibration and Stability Characteristics of FGM Plates Subjected to Nonlinearly Varying Edge Loads
(Springer Science and Business Media Deutschland GmbH, 2023) Swaminathan, K.; Hirannaiah, S.; Rajanna, T.
In this article, the consequences of porosity type of imperfection on vibration and stability characteristics of Functionally Graded Material (FGM) plate members are examined. Since it is challenging to predict the type of porosity distribution in the plate, four diverse varieties of porosity distributions varying through the thickness are considered during the modelling of FGM plates. The porosity effect is included in material modelling by means of modified rule of mixture. The in-plane edge loads acting on plates are seldom uniform in nature during the operational condition. And hence, vibration and stability characteristics of the FGM plates comprising porosity is analyzed considering nonlinearly varying in-plane edge load incorporating Finite element (FE) method. The numerical outcomes obtained are compared to those reported in the literature to help decide the formulation's correctness. The effect of geometric configuration, volume fraction exponent, porosity and loading on vibration and stability characteristics of FGM plate member with porosity is investigated. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Effect of slag and solid activator on flowability and compressive strength of fly ash based one-part geopolymer pastes
(Elsevier Ltd, 2023) Srinivasa, A.S.; Swaminathan, K.; Yaragal, S.C.
The geopolymerization process has led to the transformation of industrial by-products into sturdy and long-lasting construction materials, such as geopolymer binders, which can be used to mitigate the massive CO2 emissions associated with the production of Ordinary Portland Cement (OPC). These binders are produced from aqueous solutions of alkali activators and alumina and silica rich industrial waste materials. Strong, caustic, and viscous aqueous solutions are used in alkali activation. Its handling, usability, and mass production are all tough, even transport and site difficulties compound these issues. The solid alumina-silica rich components, solid alkali activators, and free water are dry mixed in this work to create a unique “one-part” or “simply add water” geopolymer binder that is equivalent to OPC in its manufacture. Researchers looked at the flowability and compressive strength properties of fly ash based one-part geopolymer mixes while adding ground granulated blast furnace slag and a solid activator (anhydrous sodium metasilicate powder). At the 25 and 50% replacement levels, GGBS was used in place of fly ash. Solid activator content varied from 8 to 16% at an interval of 2% for each replacement level of GGBS. Microstructural and mineralogical alterations were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. According to the findings of the tests, the flowability and compressive strength improved with decreasing slag and solid activator concentration. It was found that activator content increments beyond 12% result in minor reduction in compressive strength, and that the highest compressive strength was measured at 50% GGBS and 12% activator content. Both flowability and compressive strength were improved by the 50% GGBS and 12% activator mixture, which also displayed symptoms of having a dense and compacted microstructure. © 2023
EFG meshless-ANN approach for free vibration analysis of functionally graded material plates on elastic foundation in thermal environments
(Taylor and Francis Ltd., 2025) K P, A.; Swaminathan, K.; Hirannaiah, S.; Pavan, G.S.
This study focuses on free vibration analysis of functionally graded material (FGM) plates supported by Winkler–Pasternak elastic foundation in thermal environment using element-free Galerkin (EFG) meshless method. Plate kinematics depend on first-order shear deformation theory. Uniform, linear, and nonlinear temperature variations through the thickness direction are considered, along with the temperature-dependent material properties. The numerical outcomes obtained from EFG method are compared with those available in the published literature to validate the proposed method’s accuracy. An artificial neural network (ANN) model that can easily predict the natural frequencies of the plate is constructed from the EFG method outcomes. Further, the effect of foundation parameters, power law index, thickness ratio, temperature variations, and different boundary conditions are investigated; results show that these significantly influence the vibration response of FGM plates supported by the elastic foundation. Increasing the temperature of FGM plates supported by the Winkler–Pasternack foundation causes a decrease in the dimensionless fundamental natural frequency, and the uniform temperature influence is greater than that of linear and nonlinear temperature variation. The proposed EFG-ANN prediction model saves approximately 98.80% computation time when predicting the natural frequency with an accuracy of approximately 98.76% compared to that by EFG meshless method alone. © 2024 Taylor & Francis Group, LLC.
Experimental study on shear strengthening of RC beams using externally bonded carbon fiber reinforced polymer sheets
(2011) Swaminathan, K.; Chethana, H.A.; Biradar, G.
This paper presents the experimental results of the Reinforced Concrete (RC) beams strengthened in shear with externally bonded Carbon Fiber Reinforced Polymer (CFRP) strips. The investigation mainly focus on the shear strengthening effect of bonded CFRP strips on the ultimate shear strength and deformation behaviour of RC beams. In total eight beams were cast, seven without any internal shear reinforcement and the eighth with internal stirrups. Out of the seven beams without any shear reinforcement, one was used as control beam and the remaining beams were strengthened with CFRP strips with different wrapping schemes. All the beams were tested under simply supported condition with four point bending. The failure process of all the beams was carefully monitored and the results with regard to strain, deflection, first crack appearance, crack propagation and the shear carrying capacity are discussed. Results showed that the crack propagation can be better arrested in beams strengthened with CFRP strips. The shear enhancement of CFRP strengthened beams were in the range of 26 to 34 percent as compared to control beam. This study shows that the use of CFRP strips significantly increases the shear capacity of RC beams. � 2011, Advanced Engineering Solutions.
Experimental study on shear strengthening of RC beams using externally bonded carbon fiber reinforced polymer sheets
(2011) Swaminathan, K.; Chethana, H.A.; Biradar, G.
This paper presents the experimental results of the Reinforced Concrete (RC) beams strengthened in shear with externally bonded Carbon Fiber Reinforced Polymer (CFRP) strips. The investigation mainly focus on the shear strengthening effect of bonded CFRP strips on the ultimate shear strength and deformation behaviour of RC beams. In total eight beams were cast, seven without any internal shear reinforcement and the eighth with internal stirrups. Out of the seven beams without any shear reinforcement, one was used as control beam and the remaining beams were strengthened with CFRP strips with different wrapping schemes. All the beams were tested under simply supported condition with four point bending. The failure process of all the beams was carefully monitored and the results with regard to strain, deflection, first crack appearance, crack propagation and the shear carrying capacity are discussed. Results showed that the crack propagation can be better arrested in beams strengthened with CFRP strips. The shear enhancement of CFRP strengthened beams were in the range of 26 to 34 percent as compared to control beam. This study shows that the use of CFRP strips significantly increases the shear capacity of RC beams. Â© 2011, Advanced Engineering Solutions.
Free vibration analysis of single and multilayered sandwich FGM plates-assessment of higher order refined theories
(2014) Swaminathan, K.; Naveenkumar, D.T.
Analytical formulations and solutions for natural frequency analysis of functionally graded material (FGM) plates based on two higher-order refined shear deformation theories with 9 and 12 degrees-of-freedom are presented. The displacement model with 12 degrees-of-freedom considers the effect of both transverse shear and normal strain/stress while the other considers only the effect of transverse shear deformation. In addition another higher-order model and the firstorder model developed by other investigators and available in the literature are also presented for the evaluation purpose. For mathematical modeling purposes, the Poisson's ratio of the material is considered as constant whereas Young's modulus is assumed to vary through the thickness according to the power law function. The equations of motion are derived using Hamilton's principle. Solutions are obtained in closed-form using Navier's technique and solving the eigenvalue equation. The accuracy of the theoretical formulations and the solution method using the present two higher-order refined models is first established by comparing the results generated in the present investigation with the 3D elasticity solutions already reported in the literature. After establishing the accuracy of predictions, benchmark results for the natural frequencies using all the four models are presented for single layer FGM plate and multi layered FGM sandwich plate with varying edge ratios and side-to-thickness ratios. � (2014) Trans Tech Publications, Switzerland.
Free vibration analysis of single and multilayered sandwich FGM plates-assessment of higher order refined theories
(2014) Swaminathan, K.; Naveenkumar, D.T.
Analytical formulations and solutions for natural frequency analysis of functionally graded material (FGM) plates based on two higher-order refined shear deformation theories with 9 and 12 degrees-of-freedom are presented. The displacement model with 12 degrees-of-freedom considers the effect of both transverse shear and normal strain/stress while the other considers only the effect of transverse shear deformation. In addition another higher-order model and the firstorder model developed by other investigators and available in the literature are also presented for the evaluation purpose. For mathematical modeling purposes, the Poisson's ratio of the material is considered as constant whereas Young's modulus is assumed to vary through the thickness according to the power law function. The equations of motion are derived using Hamilton's principle. Solutions are obtained in closed-form using Navier's technique and solving the eigenvalue equation. The accuracy of the theoretical formulations and the solution method using the present two higher-order refined models is first established by comparing the results generated in the present investigation with the 3D elasticity solutions already reported in the literature. After establishing the accuracy of predictions, benchmark results for the natural frequencies using all the four models are presented for single layer FGM plate and multi layered FGM sandwich plate with varying edge ratios and side-to-thickness ratios. Â© (2014) Trans Tech Publications, Switzerland.
Higher order refined computational model with 12 degrees of freedom for the stress analysis of antisymmetric angle-ply plates - analytical solutions
(2007) Swaminathan, K.; Patil, S.S.
Analytical formulations and solutions for the stress analysis of simply supported antisymmetric angle-ply composite and sandwich plates hitherto not reported in the literature based on a higher order refined computational model with twelve degrees of freedom already reported in the literature are presented. The theoretical model presented herein incorporates laminate deformations which account for the effects of transverse shear deformation, transverse normal strain/stress and a nonlinear variation of in-plane displacements with respect to the thickness coordinate thus modelling the warping of transverse cross sections more accurately and eliminating the need for shear correction coefficients. In addition, two higher order computational models, one with nine and the other with five degrees of freedom already available in the literature are also considered for comparison. The equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier's technique by solving the boundary value problem. Accuracy of the theoretical formulations and the solution method is first ascertained by comparing the results with that already available in the literature. After establishing the accuracy of the solutions, numerical results with real properties using all the computational models are presented for the stress analysis of multilayer antisymmetric angle-ply composite and sandwich plates, which will serve as a benchmark for future investigations. © 2006.