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دسترسی آزاد مقاله
1 - Static Bending Analysis of Foam Filled Orthogonally Rib-Stiffened Sandwich Panels: A Mathematical Model
S Soleimanian A Davar J Eskandari Jam M Heydari BeniThe current study presents a mathematical modeling for sandwich panels with foam filled orthogonally rib-stiffened core using Heaviside distribution functions. The governing equations of the static problem have been derived based on classical lamination theory. The pres چکیده کاملThe current study presents a mathematical modeling for sandwich panels with foam filled orthogonally rib-stiffened core using Heaviside distribution functions. The governing equations of the static problem have been derived based on classical lamination theory. The present model contains three displacement variables considering all of the stiffness coefficients. A closed form solution using Galerkin’s method is presented for simply supported sandwich panels with foam filled orthogonally rib-stiffened core subjected to uniform lateral static pressure. Compared to previous researches, the present work is comprehensive enough to be used for symmetric, unsymmetric, laminated or filament wound panels with orthogrid stiffeners. The accuracy of the solution is checked both through comparisons with previous works, and the results of simulation with ABAQUS software. پرونده مقاله -
دسترسی آزاد مقاله
2 - Closed-Form Formulation for Bending Analysis of Functionally Graded Thick Plates
M Shaban M. J KhoshgoftarDue to their continuous material variation and eliminating the mismatch stress field in the thickness direction, Functionally Graded Materials (FGMs) have found wide applications in aerospace and mechanical engineering. This article presents closed-form solution for thi چکیده کاملDue to their continuous material variation and eliminating the mismatch stress field in the thickness direction, Functionally Graded Materials (FGMs) have found wide applications in aerospace and mechanical engineering. This article presents closed-form solution for thick functionally graded plate based on three-dimensional elasticity theory. To this end, first, the characteristic equation of FG plate is derived and general closed-form is obtained analytically. Both positive and negative discriminant of characteristic equation is considered and solved. The presented method is validated with finite element results by considering isotropic thick plate. Several parametric studies are carried out to investigate the effect of geometric and material parameters. The aim of this research is to present analytical solution form for thick FG plate and work out the problem of inconsistency for corresponding displacements field. The presented solution can be used to examine accuracy of various plate theories such as first-order, third order shear deformation theories and other equivalent plate theories. پرونده مقاله -
دسترسی آزاد مقاله
3 - An Efficient Co Finite Element Approach for Bending Analysis of Functionally Graded Ceramic-Metal Skew Shell Panels
G Taj A ChakrabartiIn this article, the prominence has been given to study the influence of skew angle on bending response of functionally graded material shell panels under thermo-mechanical environment. Derivation of governing equations is based on the Reddy’s higher-order shear d چکیده کاملIn this article, the prominence has been given to study the influence of skew angle on bending response of functionally graded material shell panels under thermo-mechanical environment. Derivation of governing equations is based on the Reddy’s higher-order shear deformation theory and Sander’s kinematic equations. To circumvent the problem of C1 continuity requirement coupled with the finite element implementation, C0 formulation is developed. A nine noded isoparametric Lagrangian element has been employed to mesh the proposed shell element in the framework of finite element method. Bending response of functionally graded shell under thermal field is accomplished by exploiting temperature dependent properties of the constituents. Arbitrary distribution of the elastic properties follows linear distribution law which is a function of the volume fraction of ingredients. Different combinations of ceramic-metal phases are adopted to perform the numerical part. Different types of shells (cylindrical, spherical, hyperbolic paraboloid and hypar) and shell geometries are concerned to engender new-fangled results. Last of all, the influence of various parameters such as thickness ratio, boundary condition, volume fraction index and skew angle on the bending response of FGM skew shell is spotlighted. Some new results pertain to functionally graded skew shells are reported for the first time, which may locate milestone in future in the vicinity of functionally graded skew shells. پرونده مقاله -
دسترسی آزاد مقاله
4 - Bending Analysis of Carbon Nanotubes with Small Initial Curvature Embedded on an Elastic Medium Based on Nonlocal Elasticity and Galerkin Method
اعظم عارفی محمود سلیمیCarbon nanotubes have an important role in reinforcing nanocomposits. Many experimental observations have shown that in the most nanostructures such as nanocomposites, carbon nanotubes (CNTs) are often characterized by a certain degree of waviness along their axial dire چکیده کاملCarbon nanotubes have an important role in reinforcing nanocomposits. Many experimental observations have shown that in the most nanostructures such as nanocomposites, carbon nanotubes (CNTs) are often characterized by a certain degree of waviness along their axial direction. In the present paper, the effects of initial curvature, influence of surrounding medium that is modeled as Winkler elastic foundation on behavior of slightly curved carbon nanotubes are investigated. To capture the small size effects, nonlocal elasticity theory is implemented. Bending governing equations are derived using the principle of minimum total potential energy and these nonlinear equations are solved by Newton Raphson method. It is shown that the larger the initial curvature, the higher deflection can occur. Furthermore, neglecting the effect of initial curvature of CNTs can lead to incorrect results. پرونده مقاله