Postbuckling Compressive Strength of Graphite/Epoxy Laminated Cylindrical Panels Loaded in Compression

The postbuckling compressive strength and collapse phenomena of composite laminated cylindrical panels with various fiber angles and width-to-length ratios are characterized by the nonlinear finite element method. For the iteration and load increment along the postbuckling equilibrium path, a modified arc-length method in which the effect of stress unloading due to failure can be considered is introduced. In the progressive failure analysis, the maximum stress criterion and complete unloading model are used. Validity of present finite element results are verified by experiment for [0 3 /90] S cylindrical panel and [0/90/±45] S plate. The postbuckling compressive strength of composite laminated cylindrical panels is independent of the initial buckling stress but high in the panel with large value of the bending stiffness in axial direction. In several of the cylindrical panels, it is observed that the prebuckling compressive failures occur and directly result in collapse before buckling.