Influence of model extension and boundary conditions on the buckling behaviour of aluminium integrally stiffened panels under uniaxial compressive loading

The aim of this paper is to investigate the influence of model extension and boundary conditions on the buckling behaviour of aluminium integrally stiffened panels under uniaxial compressive loading. Two types of models with different extensions, the multi-span model and half-multi-half span model, are employed and combined with various boundary conditions, namely fixed, simply supported and symmetric boundary conditions. The fabrication related imperfections, such as initial deformations, material softening in heat-affected zone and residual stresses are simulated in the numerical analysis. The results show some new evidence of the effect of different model extension and boundary conditions on the numerical results for the ultimate strength of aluminium integrally stiffened panels, which also explains the discrepancy between the experimental data and numerical results of aluminium integrally stiffened panels with the same cross-section and span length. The configurations of model extension and boundary conditions are proposed for numerical simulations and experimental tests of aluminium integrally stiffened panels.