Buckling behavior of stiffened laminated plates

A layerwise (zigzag) finite element formulation is developed for the buckling analysis of stiffened laminated plates. The laminated plate is discretized into layers along the thickness direction. Each layer of the laminated plate is modeled by the degenerated shell elements, and the stiffener is modeled by the general 3-D beam elements. Layers are stacked together according to the interlayer continuity. In-plane displacements are considered in the derivation of geometric stiffness matrix. The advantage of the proposed model is its applicability to both thin and thick laminated plates. The significance of this study lies in the disclosure of the interaction between the lateral buckling of the stiffener and the buckling of the laminate. The inverse iteration method is adopted to extract the lowest eigenvalue corresponding to buckling. Parametric and comparative studies are conducted for different plate aspect ratios, plate thickness to length ratios, degrees of layer orthotropy, ply orientations, and stiffener depth to plate thickness ratios.