Buckling of longitudinally stiffened plates in bending and compression

The nonlinear stiffness equations that predict local and post-local buckling of plates and plate assemblies are given. These equations are validated by accurate predictions of independent test results. The elastic local buckling of longitudinally stiffened web plates in combined bending and compression is considered. Graphs which may be used to predict the optimum position of a stiffener are presented. The relationship between the area and second moment of area of a stiffener of finite dimensions that optimizes the local buckling coefficient is given for various eccentricities of end load. The post-local buckling of a longitudinally stiffened plate in uniform compression and pure bending is also considered. It is shown that the provision of a longitudinal stiffener, of proportions to enforce a node at the plate–stiffener junction, enhances significantly the postbuckling response of the plate with regard to the serviceability limit state, particularly for the case of pure bending. Key words: bending, compression, finite strips, local buckling, plates, postbuckling, stiffeners, webs.