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- A comprehensive review on analysis of nanocomposites: from manufacturing to properties characterizationPublication . M, Vinyas; Athul, S. J.; Harursampath, D.; Loja, Amélia; Trung, Nguyen ThoiThe study of nanocomposites in its diverse scientific fields has increased dramatically over the years with numerous theoretical and experimental techniques emerging and redefining the process of synthesis, analysis and cost control methodologies of nanocomposites. The present review is an attempt to identify the various methodologies, techniques, theories and formulations that are used in nanocomposite technology. As an overall qualitative appreciation it is possible to conclude that the diversity of processes involved in the manufacture and analysis of nanocomposites, impacts them differently, influencing their physical nature, chemical behaviour, biological interactions, optical properties and production costs which consequently may introduce some constraints to their application. Hence, a critical review on the best methodology would remain inconclusive. This work intends to collect and relate publications on different fields of the nanocomposites technology and application fields, aiming at contributing to achieve a wide perspective of different aspects of the nanocomposites processes and theories and with this, being an aid to ease and raise the production and analysis of nanocomposites to a higher level.
- Influence of interphase on the multi-physics coupled frequency of three-phase smart magneto-electro-elastic composite platesPublication . Vinyas, Mahesh; Sunny, K. K.; Harursampath, D.; Trung, Nguyen-Thoi; Loja, AméliaThe present article researches the influence of piezoelectric interphase thickness on the coupled frequency response of three-phase smart magneto-electro-elastic (TPS-MEE) plates with the aid of Reddy’s third-order shear deformation theory (RTSDT). A three-phase smart composite constituted of CoFe2O4 piezomagnetic matrix embedded with carbon fibers in the piezoelectric shell is considered for evaluation. The coupling characteristics of the smart carbon/PZT-5A (PZT-7A)/CoFe2O4 composites significantly changes with the interphase thickness of piezoelectric interphase. Thereby the stiffness and the natural frequency of the structure composed of these three-phase MEE materials drastically changes. A finite element (FE) formulation has been derived incorporating Hamilton’s principle. The equations of motion are obtained through condensation technique. The results reveal a significant effect of interphase thickness on the natural frequency of the three-phase smart magneto-electroelastic plate. Further, a special attention has been paid on evaluating the influence of carbon fiber/piezoelectric volume fraction on the free vibration behaviour of TPS-MEE plate. Also, a parametric study has been performed to investigate the effect of boundary conditions, aspect ratio and length-to-width ratio.
- Numerical analysis of the vibration response of skew magneto-electro-elastic plates based on the higher-order shear deformation theoryPublication . Vinyas, M.; Nischith, G.; Loja, Amélia; Ebrahimi, Farzad; Duc, N. D.This work addresses the problem of the three-dimensional free vibration behavior of skew magneto-electro-elastic plates under the framework of a higher order shear deformation theory. To this end, the finite element method was adopted considering the Hamilton's principle. The results obtained from the present finite element model are verified with the simulation results of COMSOL software. Further, a parametric study is carried out to evaluate the influence of boundary conditions, stacking sequence, aspect ratio, and the length-to-width ratio. A special emphasis has been given to the natural frequency characteristics of multiphase skew magneto-electroelastic plates as well. The results from the present analyses allow concluding on the significant influence that the geometrical skewness has on the free vibration behavior of these plates.
- Effect of BaTiO3/CoFe2O4 micro-topological textures on the coupled static behaviour of magneto-electro-thermo-elastic beams in different thermal environmentPublication . M, Vinyas; Kattimani, S. C.; Loja, Amélia; Mahesh, VishwasThe use of composite materials with multifunctional capabilities is an increasing requirement for structures or components where the sensory function is accompanied by the diagnosis and the actuation functions, such as autonomic, adaptive or self-sustaining systems. In this context, the present study aims to characterize the coupled response of magneto-electro-thermo-elastic (METE) beams made from Barium Titanate (BaTiO3) and Cobalt Ferric Oxide (CoFe2O4) composite having various micro-topological textures, as well as their static response when submitted to different temperature distribution profiles. To this purpose, a three-dimensional finite element accounting for the coupling between the multiple physical fields in presence, is developed and implemented. The spatial heterogeneous BaTiO3/CoFe2O4 microstructure is also assessed by considering typical Body Centered Cubic (BCC), Face Centered Cubic (FCC) and Simple Cubic (SC) spatial packing arrangements. A special attention is paid to the influence of these micro-topological structures on the pyroeffects and its contribution towards the direct and derived quantities of the METE beam. The results obtained, suggest that the composite heterogeneous microstructure have a relevant influence on the static response of the METE beam in thermal environment.
- Mechanical behavior of a sandwich plate with aluminum foam core, using an image-based layerwise modelPublication . Mota, A. F.; Loja, Amélia; Barbosa, J.I.; Vinyas, M.Functionally graded materials are an advanced type of composite materials whose properties’ spatial evolution can be designed through the definition of the spatial distribution of the constituent phases’ mixture. This feature is particularly important if specific non-homogeneous properties’ requirements are required without introducing abrupt phases’ transitions, as happens in laminated materials. Porosities’ distributions within these materials, may constitute a design requisite for some applications, such as medical implants, but can also be highly undesirable in other cases such as for aeronautical applications. Regardless the specific situation, its characterization is of high importance to the prediction of the resulting materials’ behavior. This work is focused on the static and free vibrations’ analysis of a sandwich plate with a porous aluminum foam core and outer aluminum skins. The porosities’ distribution is modeled by different fitting functions, based on data obtained from a preliminary image processing stage of X-ray CT image of the sandwich plate’ cross-section. A layerwise approach is considered for subsequent numerical simulations’ purpose, where the sandwich skins’ kinematics are modeled using the first order shear deformation theory, while the core is modeled by a higher order shear deformation theory. Fitting functions’ influence on the plate’ behavior is also assessed.