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Displaying 8341-8350 on page 835 of 8411. Per Page  
  • A Phenomenological Model for Desorption in Polymers
  • Abstract A phenomenological formulation is adopted to investigate desorption in polymers. The speed of the front is studied and the well-posedness of the general model is analyzed. Numerical simulations illustrating the dynamics of the desorption process described by the proposed model are included.
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  • Experimental and Numerical Study of Micro Deep Drawing of Copper Single Crystal
  • Abstract One of the problems in a micro-forming process is the grain size effect, which means the formed part consists of a single grain or several grains sometimes, so the material shows anisotropic or heterogeneous. Under these conditions, a conventional method, which based on the isotropic and homogeneous material hypothesis, is not suitable. In this paper, Experimental investigations into micro deep drawing of the copper single crystal were carried out and the pattern of the micro-cup and the drawing force were observed. Using crystal plasticity theory, a user material subroutine (VUMAT) was built and linked to ABAQUS, and the micro deep…
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  • Three-Dimensional Solutions of Functionally Graded Piezo-Thermo-Elastic Shells and Plates Using a Modified Pagano Method
  • Abstract A modified Pagano method is developed for the three-dimensional (3D) coupled analysis of simply-supported, doubly curved functionally graded (FG) piezo-thermo-elastic shells under thermal loads. Four different loading conditions, applied on the lateral surfaces of the shells, are considered. The material properties of FG shells are regarded as heterogeneous through the thickness coordinate, and then specified to obey an exponent-law dependent on this. The Pagano method, conventionally used for the analysis of multilayered composite elastic plates/shells, is modified to be feasible for the present analysis of FG piezo-thermo-elastic plates/shells. The modifications include that a displacement-based formulation is replaced by a mixed…
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  • A General Magnetoelastic Coupling Theory of Deformable Magnetized Medium Including Magnetic Forces and Magnetostriction Effects
  • Abstract From the viewpoint of energy, a general magnetoelastic coupling theory including magnetic forces and magnetostriction effects is proposed for deformable magnetized medium. Firstly, a Taylor series expansion of independent variables of stress and magnetization in the elastic Gibbs free energy function is applied to obtain a polynomial expression; and then based on the magnetoelastic coupling mechanism, appropriate transcendental functions are substituted for some terms in a polynomial constitutive relationship derived by way of substituting the polynomial Gibbs free energy function in thermodynamic equations to achieve a more compact magnetostrictive constitutive relationship. The numerical simulation exhibits that the predicted magnetostrictive strain…
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  • Computer Modeling of Ionic Conductivity in Low Temperature Doped Ceria Solid Electrolytes
  • Abstract Solid oxides, such as ceria (CeO2) doped with cations of lower valance, are potential electrolytes for future solid oxide fuel cells. This is due to the theoretically high ionic conductivity at low operation temperature. This paper investigates the feasibility of two potential electrolytes which are samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) to replace the traditional yttria-stablized zirconia (YSZ). Molecular simulation techniques were employed to study the influence of different dopant concentrations at different operation temperatures on the ionic conductivity from the atomistic perspective. Simulation results show that the optimized ionic conductivity occurs at 11.11mol% concentration using both dopants of…
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  • A Computational Approach to Investigate Electromagnetic Shielding Effectiveness of Steel Fiber-Reinforced Mortar
  • Abstract The electromagnetic shielding effectiveness of steel fiber-reinforced mortar was numerically examined in this study. A series of numerical analysis on twenty-seven types of specimens of different diameters, lengths, and volume fractions of fibers were conducted using the FE program HFSS to investigate the effect of the dimensions of steel fibers and the amount of fibers added to the mortar on the shielding effectiveness. S-parameters of some specimens were experimentally measured by the free space method and the experimentally measured S-parameters were compared with those computed in order to verify the present numerical analysis method. It was found that smaller diameters…
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  • Buckling Analysis of Plates Stiffened by Parallel Beams
  • Abstract In this paper a general solution for the elastic buckling analysis of plates stiffened by arbitrarily placed parallel beams of arbitrary doubly symmetric cross section subjected to an arbitrary inplane loading is presented. According to the proposed model, the stiffening beams are isolated from the plate by sections in the lower outer surface of the plate, taking into account the arising tractions in all directions at the fictitious interfaces. These tractions are integrated with respect to each half of the interface width resulting two interface lines, along which the loading of the beams as well as the additional loading of…
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  • Atomistic Modeling of the Structural and Thermal Conductivity of the InSb
  • Abstract A new parametrization for the previous empirical interatomic potential for indium antimonite is presented. This alternative parametrization is designed to correct the energetic sequence of structures. The effective empirical interatomic potential proposed consists of two and three body interactions which has the same functional form of the interatomic potential proposed by Vashishta et. al. to study other semiconductors (Branicio et al., 2003; Ebbsjo et al., 2000; Shimojo et al., 2000; Vashishta et al., 2008). Molecular dynamics simulations (MD) are performed to study high pressure phases of InSb up to 70 GPa and its thermal conductivity as a function of temperature.…
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  • Singular Superposition/Boundary Element Method for Reconstruction of Multi-dimensional Heat Flux Distributions with Application to Film Cooling Holes
  • Abstract A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling hole centerline) with a given…
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  • The Boundary Contour Method for Piezoelectric Media with Quadratic Boundary Elements
  • Abstract This paper presents a development of the boundary contour method (BCM) for piezoelectric media. Firstly, the divergence-free of the integrand of the piezoelectric boundary element method is proved. Secondly, the boundary contour method formulations are obtained by introducing quadratic shape functions and Green's functions (Computer Methods in Applied Mechanics and Engineering1998;158: 65-80) for piezoelectric media and using the rigid body motion solution to regularize the BCM and avoid computation of the corner tensor. The BCM is applied to the problem of piezoelectric media. Finally, numerical solutions for illustrative examples are compared with exact ones. The numerical results of the BCM…
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