ABSTRACT
Advanced non-linear buckling models of thin-walled stiffened panels are developed and implemented into new and user friendly Personal Computer interfaces for fast and informative strength evaluation. The buckling models, called PULS (Panel Ultimate Limit State), covers geometrical proportions of plates and stiffeners typically used in ship hulls and offshore constructions. The models are recognized by Det Norske Veritas for strength evaluations of elements such as girders, deck panels, bottom structures, bulkheads etc.
The PULS buckling models are founded on the large deflection plate theory of Marguerre and von Karman. Discretizations of the buckling displacements follow the Rayleigh-Ritz method using Fourier series expansions. Energy principles are used for establishing the algebraic non-linear equilibrium equations and incremental perturbation techniques are used for solving these. By limiting the degrees of freedom and solving the non-linear geometrical problem, using hot spot stress control for ultimate strength assessment, the time required for strength of a given panel is of the order of one second.
