An investigation into the static response of fiber-reinforced open conical shell panels considering various types of orthotropy

Abstract

In this study, bending of composite open conical shell panels subjected to various distributed mechanical loads with various types of orthotropy is investigated. The stiffness coefficients are assumed to be functions of the meridional and circumferential coordinates in panels, which are produced by various methods for the realistic applications. In the first case of orthotropic open conical shell panels, the orientation of fibers are assumed to be in the meridional and circumferential directions. The stiffness coefficients of this type of fiber-reinforced panel are usually assumed to be constant. It is shown that due to the geometry of the conical surface, thickness of laminate will be changed along the meridional direction. The effect of stiffness variation on the response of panel is considered for the first time. In the case of open conical shell panel, which is fabricated by molding the prepreg layers around a conical-shaped mandrel, angle between fibers and meridional lines and, consequently, stiffness coefficients are assumed to be functions of the circumferential coordinates. In the third type, open conical shell panel can be made by cutting from a filament wound circular conical shell. In this case, thickness and ply orientation are functions of the shell coordinates. In this article, different path definitions for variable stiffness filament wound shells are considered. The inclusion of this geometric complicating effect in static analysis will add considerably to the complication and cost of a solution scheme. This article presents some results to show when these assumptions have a significant effect on the end result. The governing equations are based on the first-order shear deformation theory. The governing equations are discretized at whole domain grid points, and the boundary conditions are implemented exactly at boundary grid points using the generalized differential quadrature method. Application of the generalized differential quadrature to the governing equations, solution domain and boundary conditions leads to a system of algebraic equations. Various combinations of clamped, simply supported and free boundary conditions are implemented. It is found that the present method can accurately analyze fiber-reinforced open conical shell panels with various types of orthotropy.