Nonlinear vibration and stability of a shallow unsymmetrical orthotropic sandwich shell of double curvature with orthotropic core

In this paper, nonlinear behaviours for a shallow unsymmetrical, orthotropic sandwich shell of double curvature with orthotropic core having different elastic characteristics have been studied by a new set of uncoupled differential equations. The face sheet may be of unequal thickness of different materials. However, a restriction that the elements radii of curvature be large compared to the overall thickness of the sandwich has been imposed. A simple approach used in the present analysis can be applied for stability as well as vibration. For the symmetrical case, where the face sheets are of equal thickness and of same materials, these equations can be shown to reduce to those given by Grigolyuk in 1957. Numerical results of a square rectangular simply supported curved plate, and of a rectangular sandwich cylindrical shell under mechanical and dynamic loading, have been computed and compared with other known results.