Comparative study between analytical and FE analysis for the ultimate strength assessment of pitted platings

The ultimate strength assessment of platings affected by pitting corrosion wastage is a basic issue for the scantling and design of ship structures. In the past, several nonlinear FE analyses were performed to investigate the incidence of pitting degree and corrosion depth on the ultimate strength of plate panels, with the main aim of providing some approximate formulations, useful at least in the preliminary project phase. Based on actual state of art, the main aim of current research is to provide an analytical formulation for the ultimate strength assessment of platings with random pitting corrosion wastage, by solving the Marguerre non-linear governing differential equations for large deflection analysis of platings in the post-buckling regime. In this respect, a comparative analysis between the analytical solution and a series of FE results is preliminarily performed for uncorroded platings, combining different levels of initial geometrical imperfections and welding residual stresses. Subsequently, the comparative analysis is extended to platings affected by pitting corrosion wastage. Hence, different levels of pitting and corrosion intensity degrees are properly combined in order to investigate the goodness of the proposed analytical formulation.