The aim of the paper is to improve the current shape limitation requirements of BS 5400: Part 3, which are known to be unduly conservative, especially when applied to assessment of existing structures. A practical method for finding the local critical stress for plate/stiffener combinations, without limitations on section slenderness, is presented. The critical component is identified for all possible buckling wavelengths, which can vary between the length of the stiffened plate and the wavelength of an encastré plate or stiffener, depending on the section geometry. For each possible wavelength, the critical stress c$ the critical component is found, when restrained by the other component, using an iterative method thut is easily programed for a desktop computer. Validation is provided by 75 finite element (FE) solutions. The
results will be incorporated in a methodfor design or assessment.
S.K.G. Chou, J.C. Chapman and P.C. Davidson