Faculty Publications
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Item 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. © 2020 Elsevier Ltd. All rights reserved.Item 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. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Vibration and stability characteristics of functionally graded sandwich plates with/without porosity subjected to localized edge loadings(Taylor and Francis Ltd., 2023) Swaminathan, K.; Hirannaiah, S.; Rajanna, T.This article investigates the influence of porosity and localized edge loads on the vibration and buckling characteristics of functionally graded material (FGM) plates using the finite element (FE) method. The analysis is carried out by choosing a single-layer FGM and two different types of FGM sandwich plates in such a way that there is no material discontinuity along the thickness direction. The porosity imperfections are accounted for in this study as criteria of stiffness reduction and are incorporated using modified power law distribution. The vibration and buckling responses are studied by considering four types of localized edge loads on plates with different porosity distributions. The application of different types of localized edge loads on the plate leads to the development of nonuniform in-plane stresses. Hence, they are computed first by using a dynamic approach before obtaining the buckling loads. The accuracy of the FE formulation is first validated for FGM plates by comparing the natural frequencies and the critical buckling loads obtained in the present investigation with the solutions already available in the literature. After validating the accuracy, detailed parametric studies have been performed on plates with varying volume fraction exponent, porosity distribution, porosity index, side-to-thickness ratio, load width ratio, aspect ratio, and support condition, and the results are presented with appropriate conclusions. A probabilistic sensitivity analysis is carried out to identify the significant parameter affecting the buckling load and natural frequency of porous FGM plates subjected to localized edge loads, which considerably aids in the design of the FGM plates. © 2022 Taylor & Francis Group, LLC.Item Vibration and Stability Characteristics of Functionally Graded Plates Subjected to Localized Edge Loadings(Springer, 2025) Swaminathan, K.; Hirannaiah, S.; Rajanna, T.In this article, the influence of various types of localized in-plane edge loadings on vibration and stability characteristics of Functionally Graded Material (FGM) plates have been studied by developing finite element (FE) code in FORTRAN. Due to the complex arrangement of plates and situations arising during the real time application, loads acting on the member are not always uniform, rather nonuniform or localized in nature. For a such loading and boundary condition, the stress distribution within an element is highly non-uniform in nature. Therefore, the buckling loads are evaluated by dynamics approach. Here, in this study FGM plate is modelled using eight-noded isoparametric element with five degrees of freedom at each node. In the FE formulations, the influence of shear deformation and rotary inertia are included. In the FGM plate, the effective materials properties are assumed to vary in the thickness direction according to power-law distribution of volume fraction of the constituents. The analysis is carried out for four types of localized edge loads. Effect of different parameters such as boundary condition, side to thickness ratios, volume fraction exponent, load width ratio and the aspect ratio of the plate is considered to study the buckling characteristics of FGM plate. From the current study, it is mainly understood that the buckling characteristics of FGM plate of various volume fraction exponent is highly influenced by the position and width of localized in-plane edge loads. © The Institution of Engineers (India) 2024.