The aim of the present study is to develop a method for predicting the buckling/post-buckling behaviour including a secondary buckling and ultimate strength of a cylindrically curved plate subjected to axial compression. The elastic large deflection analysis of curved plates with initial imperfection, simply supported along four edges, is performed by applying FEM. Analytical formulation is made based on the theory of the elastic large deflection analysis. The elastic buckling/postbuckling behaviour including a secondary buckling is investigated varying the thickness, aspect ratio and curvature of plates as well as the shape and magnitude of the initial imperfection. The buckling/plastic collapse behaviour and ultimate strength are also examined by applying FEM. It is shown that Faulkner's ultimate strength formula developed for a flat plate can allow a reasonable estimate of ultimate strength of the curved plate with relatively small flank angle, when the newly defined slenderness parameter considering the increase of the elastic buckling strength due to curvature is applied. The effect of the secondary buckling on the ultimate strength is discussed.
Cylindrically curved plate members have been used in various applications including ship structures. The typical examples are deck plating with a camber, a side shell, and a bilge circle part. The structural performance of curved plates is influenced by different types of failure modes, and thus the ultimate strength and buckling strength must be investigated. It has been believed that such cylindrically curved plates can be modeled fundamentally by a part of a cylinder subjected to axial loading produced by hull girder bending. From the previous studies on the estimations using the cylinder models, generally curvature increases the buckling strength of a curved plate subjected to axial compression, and also the ultimate strength (Park et al, 2008). Maeno et al. (2003, 2004) performed a series of elastoplastic large deflection analysis to investigate the buckling/plastic collapse behaviour of ship's bilge strakes, typical in tanker and bulk carrier, which are unstiffened curved thick plates subjected to axial compression.
