The effect of distortion on the buckling strength of stiffened panels

This paper predicts the behaviour of stiffened plates with different distortion levels in order to address a rational structural design procedure, as pre-existing and fabrication-related (like weld-induced) initial geometrical distortion is of great importance from a structural design point of view. The range of scantlings, the distortion types and levels were chosen based on panels used at BVT Surface Fleet Ltd., where Type 45 destroyers were under construction. An analytical relation is presented based on Perry's column approach to establish the variation of buckling strength against the geometrical distortion. A parametric form of non-linear finite element (FE) analysis using ABAQUS was carried out under axial loading condition to predict the behaviour and the buckling strength. The effect of residual stress is not considered in this study. A new strength parameter is proposed to represent buckling strength, which takes into account the inelastic post-buckling behaviour of the structure. The results from FE analysis are plotted in non-dimensional terms and some important conclusions are arrived at.