Computational model for local buckling of compressively loaded omega-stringer-stiffened panels

Abstract

Thin-walled composite structures are used in applications such as aircraft and spacecraft due to their low weight and corresponding high stiffness properties. To optimize the potential of these structures to the fullest extent, a complete understanding of their stability behavior is required. Thereby, uniaxial compression describes an important load case that is investigated. A closed-form analytical method based on the energy method for determining the local buckling load of omega-stringer-stiffened panels is presented. The stiffened panel under consideration consists of the skin plate with eccentrically attached stringer feet along the longitudinal sides of the panel, while the remaining part of the omega-stringer is modeled by corresponding elastically restrained edges. Due to the applied stringer feet, stiffness discontinuities occur in the stiffened panel. This is covered by the presented method, whereas in comparable studies in the literature, a homogeneous stiffness is often assumed across the entire panel. To evaluate the new analysis method, a comparison with the numerical solution of the corresponding Levy-type ´solution and the finite element analysis is being drawn.

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