In this paper, mechanical buckling analysis of composite annular sector plates with bean shape cut out is studied. Composite material sector plate made of Glass-Epoxy and Graphite-Epoxy with eight layers with same thickness but different fiber angles for each layer. Mechanical loading to form of uniform pressure loading in radial, environmental and biaxial directions is assumed. The method used in this analysis is three dimensional (3D) finite elements based on the elasticity relations. With zero first and second variation of potential energy of the entire annular sector plate, we find stability equation. Green non-linear displacement strain relations to obtain geometric stiffness matrix is ​​used. Unlike many studies, in present work three dimensional finite elements method has been used with an eight node element and meshing in the thickness direction is done, too. The bean shaped cut out in the sector has increased the complexity of the analysis. The continuing, effect of different parameters including cut out dimensions, fiber angles of layers, loading direction and dimensions of the annular sector plate on the mechanical buckling load has been investigated and interesting results have been obtained. پرونده مقاله

In this paper, semi-analytical method for asymmetrical eccentrically stiffened FGM cylindrical shells under external pressure and surrounded by a linear and non-linear elastic foundation is presented. The proposed linear model is based on two parameter elastic foundation Winkler and Pasternak. According to the von Karman nonlinear equations and the classical plate theory of shells, strain-displacement relations are obtained. The smeared stiffeners technique and Galerkin method, used for solving nonlinear problem. To finding the nonlinear dynamic response of fourth order Runge-Kutta method is used. The effect of parameters asymmetrical eccentrically stiffened on the nonlinear dynamic buckling response of FGM cylindrical shells have been investigated. پرونده مقاله