Nonlinear analysis of cylindrical sandwich shells with porous core and CNT reinforced face-sheets by higher-order thickness and shear deformation theory

Abstract

This paper presents the nonlinear static analysis of circular cylindrical sandwich shells using a higher-order thickness and shear deformation theory with nine kinematic parameters. The sandwich shell consists of a functionally graded porous core perfectly bonded with two carbon nanotubes (CNT) reinforced composite face sheets. The gradation is done in the thickness direction using three different types of distributions. An equivalent single layer theory is adopted to develop the model by assuming continuous displacements and strain functions across the thickness of the shell. The in-plane displacements and transverse deflections are expanded as third and fourth-order functions of thickness coordinate, respectively. The governing differential equations for the circular cylindrical shell are derived using the principle of minimum total potential energy and further discretized into algebraic equations by employing the Galerkin's method. These equations of motion are solved by adopting the arc-length continuation method, and the shell is analyzed for both the cases of displacement independent (radial distributed load) and displacement dependent (actual pressure) static pressurization. A parametric study is conducted to see the effect of different porosity coefficients, core-to-face sheet thickness ratios, porosity distributions, and boundary conditions.