Nonlinear structural response of geometrically imperfect skewed sandwich FGM plates with material uncertainities (MS)

Abstract

Functionally graded material (FGM) has been recognized as a potential candidate to be used in the high temperature applications such in aero craft, space shuttle industries. FGM is microscopically inhomogeneous materials having the graded variation of material properties in the preferred direction in term of the volume fractions of constituent materials. These materials are usually made of ceramics and metals. Metal provides the strength to the structure, whereas ceramic helps to withstand the high thermal gradient. In the presence of high temperature gradient, the ceramic metal interface leads to some distortion. Such conditions can be observed in a nuclear power plant having continuous fission reactions. To withstand such type of high thermal gradient during service life the ceramic and metallic sheets have been integrated to the graded superstructures. This construction is known as the functionally graded sandwich structure with FGM core and homogeneous face sheets. The complex processing of the functionally graded materials leads to the inclusion of the uncertainties and geometric imperfection in the structures. In order to obtain the accurate and realistic response of the structures these parameters needs to be incorporated in the analysis. The present study investigates the nonlinear deterministic and stochastic response of the functionally graded skew sandwich plates with initial geometric imperfections. Reddy’s higher shear deformation order theory (HSDT) has been employed in the study. Von-Karman strain assumptions have been used to model the nonlinearity in the system. Variational principle has been used to derive the governing differential equations. Direct iterative method with finite element methodology have been used to solve nonlinear system of equations. The convergence and comparison studies have been performed to show the effectiveness and reliability of the present formulation. A large number of examples have been solved to assess the effect of various design parameter on structural response of skew sandwich FGM plates.