Load shortening characteristics of marine grade aluminium alloy plates in longitudinal compression

• Welded aluminium alloy plate is now an established material in the marine industry.
• Numerical analyses are completed on aluminium alloy plates in uniaxial compression.
• The effect of several parameters affecting the buckling characteristics are assessed.
• The heat affected zone caused by welding significantly affects plate strength.
• The effect is shown to be more pronounced for low slenderness 6xxx series plates.

This study presents detailed and rigorous numerical analysis for a parametric series of unstiffened aluminium plates typical of those used in lightweight ships and equivalent thin walled stiffened structures. The study is undertaken with a nonlinear finite element analysis procedure using ABAQUS. The strength behaviour of the plates under a progressively increasing longitudinal in-plane load are shown to be affected by a number of parameters including the alloy, geometric imperfection shape, heat affected zone distribution, level of heat softening and residual stress distribution. The comparative influences of these various factors, some of which are specific to welded aluminium structure, are explored to determine which must be accounted for in the development of a parametric series of design curves.