Composite panels design based on post-buckling state with combined loading

Abstract

Buckling is possible for thin composite skins of light aircraft wing high-lift devices loaded above limit level. Aim of this work is to create a method for orthotropic panels minimal thickness definition with possible post-buckling behavior considering residual strength support. Hinge supported composite panels loaded in compression and shear jointly are considered. Method based on analytic solution of non-linear problem and design method by post-buckling state is suggested in the paper. In order to explain peculiarities of above-mentioned method examples of panels design loaded with tangential force supporting strength and stability are shown in this work. It is demonstrated that for panels minimal thickness calculation by strength, stability, and post-buckling behavior conditions corresponding linear, second- and third-degree equations in unknown thicknesses are derived. In order to develop design method by post-buckling state with combined loading analytic solution of non-linear problem using Bubnov-Galerkin method is shown in the paper. Chai criterion including all components of acting forces and stress critical values for residual strength has been used for composite package based on the conditions of combined loading. Variants of developed applied methods of design based on post-buckling state with only tangential force acting and with combined loading by compression and shear flows are shown in this work.