Browsing by Author "Twinkle, C.M."

Filter results by typing the first few letters
Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Dynamic and buckling response modelling of functionally graded graphene oxide powder(GOP) reinforced cylindrical panels: Influence of GOP grading and non-uniformly, partially distributed edge loads.
    (Elsevier Ltd, 2022) Twinkle, C.M.; Jeyaraj, J.
    Influence of non-uniform, partial edge loads and graded reinforcement of graphene oxide powder (GOP) on vibration and buckling behaviour of cylindrical panel is illustrated. A semi-analytical approach based on higher order shear deformation theory and Galerkin's approach is used to obtain the results. Initially, the membrane stress resultants due to the applied edge loads are developed through Airy's stress function expansion. Then the stress resultants are evaluated through the minimisation of strain energy. Followed by this, equations of motion are obtained based on Hamilton's principle and the stress resultants. Influence of loading of GOP quantity, nature of grading of GOP, nature of non-uniform and partial edge loads on critical buckling coefficient and fundamental frequency and mode shapes are investigated. It is noted that the buckling and vibration characteristics are sensitive to the nature of GOP grading, GOP loading and nature of variation in edge loads. Furthermore, the fundamental buckling mode is not always typical (1, 1) mode and (2, 1) mode is observed as the buckling mode according to the variation in aspect ratio and nature of edge loads. It is found that near critical buckling load, the fundamental vibration mode changes to (2,1) from (1,1) for parabolic and partial edge loading cases for the panels with aspect ratio higher than 1.3. © 2022 Institution of Structural Engineers
  • No Thumbnail Available
    Item
    Free vibration modes of rectangular plate under non-uniform heating: An experimental investigation
    (Elsevier Ltd, 2020) Twinkle, C.M.; Jeyaraj, J.; Vasudevan, V.
    Experimental studies carried out to investigate the influence of local heating on vibration mode shapes of an isotropic plate are presented. Different types of temperature fields were created by keeping the heating source at different locations. The deflection vs temperature curve is used to estimate the critical buckling temperature of the plate using inflection point method. The plate was exposed to different levels of elevated temperature as a function of buckling temperature and natural frequencies and mode shapes of the plate are estimated experimentally. Experimental investigation revealed that the effect of heating on vibration modes of the plate is significant. With the increase in elevated temperature, decrease in free vibration frequencies, shifting of nodal and anti-nodal positions and jumping of the modes are observed clearly. Experimental results associated with temperature vs deflection curve, natural frequencies and mode shapes at elevated temperature are compared with numerical results based on finite element method and found that the results are in good agreement. © 2020 Institution of Structural Engineers
  • No Thumbnail Available
    Item
    Stability and dynamic behavior of porous FGM beam: influence of graded porosity, graphene platelets, and axially varying loads
    (Springer Science and Business Media Deutschland GmbH, 2022) Priyanka, R.; Twinkle, C.M.; Jeyaraj, J.
    This paper investigates the free vibration and buckling behaviors of functionally graded graphene platelets (FG-GPLs) reinforced porous beam under axially variable loads. The internal pores and GPLs are either uniformly or non-uniformly distributed along the thickness direction. Halpin–Tsai micromechanics model is used to calculate the effective elastic modulus. The variation of Poisson’s ratio along the thickness and the relation between mass density and porosity coefficients are determined using mechanical properties of closed-cell solid under the Gaussian random scheme. The equilibrium equations are derived by Hamilton’s principles, and critical buckling load and dimensionless natural frequency are determined by Ritz formulation. Results revealed that buckling and free vibration behavior of the porous FG-GPL beam are influenced by the GPLs grading pattern and the type of axially varying load. Furthermore, the grading pattern of porosity has more influence on the buckling behavior compared to the free vibration behavior. It is also observed that buckling mode and the fundamental vibration mode of the porous FG-GPL are influenced by the loading conditions and remain unaffected by the grading pattern of porosities and GPLs. © 2021, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.
  • No Thumbnail Available
    Item
    Static stability and vibration behavior of graphene platelets reinforced porous sandwich cylindrical panel under non-uniform edge loads using semi-analytical approach
    (Elsevier Ltd, 2022) Twinkle, C.M.; Jeyaraj, J.
    Buckling and free vibration characteristics of sandwich cylindrical panel with porous functionally graded graphene platelets (FG-GPL) core are investigated using semi-analytical approach. The effective mechanical properties are obtained by using properties of open cell foams and Halpin–Tsai micro mechanical model. The governing equations are obtained using Hamilton's principle, considering a higher order theory to account the transverse shear and solved by Galerkin's method. Effects of nature of in-plane edge load, distribution of porosity and GPL, porosity coefficient, GPL loading, core to total thickness ratio are analyzed in detail. It is shown that for a FG-GPL core sandwich cylindrical panel with high core thickness, even at higher amount of porosity the buckling resistance and free vibration frequency can be improved by properly tailoring both the GPL and porosity distribution. Moreover, a much variation in buckling and free vibration response with the type of in plane loading is observed and evident mode shape changes are observed with increase in aspect ratio. The cylindrical sandwich panel having a core with D-PD porosity variation and I-GPL-P pattern of GPL distribution has the maximum buckling resistance and free vibration frequency value. © 2021 Elsevier Ltd