Closed-form methodology for the structural analysis of stiffened composite plates with cutouts and non-uniform lay-up

Abstract

Building upon the methodology developed in prior studies, which utilized the Lekhnitskii formalism to address composite plates featuring cutouts, varying thicknesses, and different stacking sequences, the present work introduces the incorporation of stiffeners. The structural configuration comprises plates and stringers, with each stringer positioned between two plate regions and subjected to both stretching and bending loads. It is important to note that no coupling between the bending and stretching responses is accounted for; therefore, lay-ups must be symmetric, and stringers must be embedded and bisymmetric. The stringers are modeled using the Euler–Bernoulli formulation with the free torsion hypothesis, while the plates are modeled using the Kirchhoff–Love formulation. Several benchmark problems are analyzed, and the results are compared with those obtained using finite element analysis (utilizing Abaqus software), demonstrating a satisfactory agreement while also showcasing competitive computational efficiency. Thus, the present methodology provides the industry with a novel tool that enables efficient parametric analysis and facilitates the most promising configurations during the initial phases of the design to be selected by engineers.