Ultimate strength assessment of continuous stiffened panels under combined longitudinal compressive load and lateral pressure

The collapse behaviour of stiffened panels under uniaxial compression load and lateral pressure are investigated in the FE analysis, in which two spans model with periodical boundary conditions are adopted. Fourier components including symmetric and asymmetric shapes are used to estimate the half-wave number of collapse for local plate by using nonlinear finite element analysis. The comparisons of the results between the FE analysis and analytical method are performed. The influences of half-wave number, direction and magnitude of initial deflection, lateral pressure as well as constraint conditions along longitudinal edges on the collapse behaviour and the ultimate strength of the stiffened panels are discussed. The ultimate strength and collapse deformation of stiffened panels are affected by not only the magnitude but also the half-wave number of initial imperfections. The lateral pressure caused by water head might increase the load carrying capacity of the stiffened panels, which depends on the collapse mode that relates with the configurations of stiffener and plate.