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F Dammak - One of the best experts on this subject based on the ideXlab platform.
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thermal post buckling analysis of Functionally Graded Material structures using a modified fsdt
International Journal of Mechanical Sciences, 2018Co-Authors: S Trabelsi, A Frikha, S Zghal, F DammakAbstract:Abstract The thermal post-buckling responses of Functionally Graded Material shell structures are reported in this paper. Geometrically nonlinear analysis based on a modified First order Shear Deformation Theory are proposed. The modified theory takes into account the shear strains with a parabolic shape function and it verifies a zero shear stresses condition at the top and bottom surfaces. For the numerical computation, four nodes shell elements are implemented. The large displacement is described by Green–Lagrange nonlinear strains. Moreover, it is assumed that the shell structures are exposed to uniform, linear and nonlinear temperature distributions through the thickness direction. The thermal and the mechanical properties are described according to a power law distribution and either temperature-independent or temperature-dependent Material properties are considered. Two numerical examples of Functionally Graded plates and cylindrical shells are presented to highlight the effectiveness and the accuracy of the present finite element procedure. The effect the geometrical parameters, the volume fraction index and boundary conditions on nonlinear responses are performed.
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discrete double directors shell element for the Functionally Graded Material shell structures analysis
Computer Methods in Applied Mechanics and Engineering, 2014Co-Authors: M Wali, A Hajlaoui, F DammakAbstract:In this paper, the accuracy and the efficiency of the 3d-shell model based on a double directors shell element for the Functionally Graded Material (FGM) shell structures analysis is studied. The vanishing of transverse shear strains on top and bottom faces is considered in a discrete form. Thus, the third-order shear deformation plate theory (TSDT) is a particular case of the discrete double directors shell model (DDDSM) used in the present work. The DDDSM is introduced to remove the shear correction factors, when using the first-order shear deformation theory (FSDT), and improve an excellent performance when compared with other works. This model can be used for static, free vibration and buckling analyses of FGM. The convergence of the proposed model is compared to other well-known formulations found in the literature. c
Dominic Cuiuri - One of the best experts on this subject based on the ideXlab platform.
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characterization of wire arc additively manufactured titanium aluminide Functionally Graded Material microstructure mechanical properties and oxidation behaviour
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Jun Wang, Chen Shen, Zengxi Stephen Pan, Dominic CuiuriAbstract:Abstract In this paper, titanium-aluminide Functionally Graded Material with a designed composition range from pure Ti to Ti-50 at% Al is successfully fabricated using the double-wire arc additive manufacturing method (WAAM). Due to the influence of Al concentration, the morphology, microstructure, mechanical properties and oxidation behaviour vary greatly along the gradient direction of the manufactured bulk. With increasing Al content from the bottom to the top, the bulk exhibits a layered structure consisting of α–β duplex structure, α-α2 lamellar structure, large α2 grains, α2-γ duplex lamellar structure and γ interdendrities structure in sequence from the bottom to the top. Microhardness and tensile strength exhibit similar trends and are comparable to those of mono-composition components. The oxidation resistance degrades at an increasing rate with decreasing Al content due to oxide breakaway occurring in the TiAl alloy matrix that consists of single α2 or α2 + α. The experimental results indicate that the WAAM method is able to produce defect free TiAl Functionally Graded Material with the desired composition gradient, suitable mechanical properties and acceptable oxidation behaviour.
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Fabrication of Fe-FeAl Functionally Graded Material Using the Wire-Arc Additive Manufacturing Process
Metallurgical and Materials Transactions B, 2016Co-Authors: Chen Shen, Jon Roberts, Zengxi Pan, Dominic Cuiuri, Huijun LiAbstract:A Functionally gradient iron-aluminum wall structure with aluminum composition gradient from 0 at. pct to over 50 at. pct is fabricated using a wire-arc additive manufacturing (WAAM) system. The as-fabricated alloy is investigated using optical microstructure analysis, hardness testing, tensile testing, X-ray diffraction phase characterization, and electron-dispersive spectrometry. The comprehensive analysis of the experimental samples has shown that the WAAM system can be used for manufacturing iron aluminide Functionally Graded Material with full density, desired composition, and reasonable mechanical properties.
E C Aifantis - One of the best experts on this subject based on the ideXlab platform.
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nanomechanics of a screw dislocation in a Functionally Graded Material using the theory of gradient elasticity
Journal of the mechanical behavior of materials, 2013Co-Authors: Kamyar M Davoudi, Hossein Davoudi, E C AifantisAbstract:The modest aim of this short article is to provide some new results for a screw dislocation in a Functionally Graded Material within the theory of gradient elasticity. These results, based on a displacement formulation and the Fourier transform technique, completes earlier findings obtained with the stress function method and extends them to the case of the second strain gradient elasticity. Rigorous and easy-to-use analytical expressions for the displacements, the strains and the stresses are obtained which are free from singularities at the dislocation line. keywords: Screw dislocation; Functionally Graded Material; Second strain gradient elasticity
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nanomechanics of a screw dislocation in a Functionally Graded Material using the theory of gradient elasticity
arXiv: Materials Science, 2010Co-Authors: Kamyar M Davoudi, Hossein Davoudi, E C AifantisAbstract:The modest aim of this short article is to provide some new results for a screw dislocation in a Functionally Graded Material within the theory of gradient elasticity. These results, based on a displacement formulation and the Fourier transform technique, extends earlier findings (Lazar, M., 2007. On a screw dislocation in a Functionally Graded Material, Mech. Res. Comm. 34, 305-311) obtained by the stress function method, to the case of the second gradient elasticity. Rigorous and easy-to-use analytical expressions for the displacements, the strains and the stresses are obtained which are free from singularities at the dislocation line.
Z H Jin - One of the best experts on this subject based on the ideXlab platform.
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an asymptotic solution of temperature field in a strip a Functionally Graded Material
International Communications in Heat and Mass Transfer, 2002Co-Authors: Z H JinAbstract:We study transient heat conduction in a strip of a Functionally Graded Material (FGM) with continuous and piecewise differentiable properties. A multi-layered Material model is first used to obtain the Laplace transforms of temperatures at the interfaces between the layers. An asymptotic analysis together with the inverse Laplace transform gives the interface temperatures for short times. An integration technique finally yields a closed form asymptotic solution of the temperature field in the FGM strip for short times
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transient thermal stress analysis of an edge crack in a Functionally Graded Material
International Journal of Fracture, 2001Co-Authors: Z H Jin, Glaucio H PaulinoAbstract:An edge crack in a strip of a Functionally Graded Material (FGM) is studied under transient thermal loading conditions. The FGM is assumed having constant Young's modulus and Poisson's ratio, but the thermal properties of the Material vary along the thickness direction of the strip. Thus the Material is elastically homogeneous but thermally nonhomogeneous. This kind of FGMs include some ceramic/ceramic FGMs such as TiC/SiC, MoSi2/Al2O3 and MoSi2/SiC, and also some ceramic/metal FGMs such as zirconia/nickel and zirconia/steel. A multi-layered Material model is used to solve the temperature field. By using the Laplace transform and an asymptotic analysis, an analytical first order temperature solution for short times is obtained. Thermal stress intensity factors (TSIFs) are calculated for a TiC/SiC FGM with various volume fraction profiles of the constituent Materials. It is found that the TSIF could be reduced if the thermally shocked cracked edge of the FGM strip is pure TiC, whereas the TSIF is increased if the thermally shocked edge is pure SiC.
Chen Shen - One of the best experts on this subject based on the ideXlab platform.
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characterization of wire arc additively manufactured titanium aluminide Functionally Graded Material microstructure mechanical properties and oxidation behaviour
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2018Co-Authors: Jun Wang, Chen Shen, Zengxi Stephen Pan, Dominic CuiuriAbstract:Abstract In this paper, titanium-aluminide Functionally Graded Material with a designed composition range from pure Ti to Ti-50 at% Al is successfully fabricated using the double-wire arc additive manufacturing method (WAAM). Due to the influence of Al concentration, the morphology, microstructure, mechanical properties and oxidation behaviour vary greatly along the gradient direction of the manufactured bulk. With increasing Al content from the bottom to the top, the bulk exhibits a layered structure consisting of α–β duplex structure, α-α2 lamellar structure, large α2 grains, α2-γ duplex lamellar structure and γ interdendrities structure in sequence from the bottom to the top. Microhardness and tensile strength exhibit similar trends and are comparable to those of mono-composition components. The oxidation resistance degrades at an increasing rate with decreasing Al content due to oxide breakaway occurring in the TiAl alloy matrix that consists of single α2 or α2 + α. The experimental results indicate that the WAAM method is able to produce defect free TiAl Functionally Graded Material with the desired composition gradient, suitable mechanical properties and acceptable oxidation behaviour.
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Fabrication of Fe-FeAl Functionally Graded Material Using the Wire-Arc Additive Manufacturing Process
Metallurgical and Materials Transactions B, 2016Co-Authors: Chen Shen, Jon Roberts, Zengxi Pan, Dominic Cuiuri, Huijun LiAbstract:A Functionally gradient iron-aluminum wall structure with aluminum composition gradient from 0 at. pct to over 50 at. pct is fabricated using a wire-arc additive manufacturing (WAAM) system. The as-fabricated alloy is investigated using optical microstructure analysis, hardness testing, tensile testing, X-ray diffraction phase characterization, and electron-dispersive spectrometry. The comprehensive analysis of the experimental samples has shown that the WAAM system can be used for manufacturing iron aluminide Functionally Graded Material with full density, desired composition, and reasonable mechanical properties.
