The effects of geometrical imperfections on the ultimate strength of aluminium stiffened plates subject to combined uniaxial compression and lateral pressure

The present study aims at determining the effects of the geometrical imperfections on the ultimate strength and load-carrying capacity of aluminium stiffened plates under combined axial compression and lateral pressure. The finite element models proposed by the Committee III.1 'Ultimate Strength' of ISSC'2003 are used in the present investigation. Initial imperfections as proposed by ISSC committee as well as those recommended by Ship Structure Committee are considered in the analyses. Models are tested using non-linear finite element elastic-plastic analyses. Aluminium alloy AA6082-T6 is selected as the material for the models. The studied models are triple-span panels stiffened by either extruded or non-extruded angle-bar profiles. Different arrangements of heat-affected zone (HAZ) are considered. The main outcomes of this study show the need for a subtle assessment of the real shapes of the initial deformations. The way they affect the ultimate strength of models is clarified through finite element analyses.