Ultimate strength prediction of corroded plates with center-longitudinal crack using FEM and ANN

Abstract

Corrosion and cracking are two main reasons for failure of plates in ships and offshore structures. In the current paper, the ultimate strength of plates with pitting corrosion and a longitudinal crack is investigated under uniform in-plane compression using non-linear finite element method (FEM). Ultimate strength of cracked-pitted plates are predicted using proper artificial neural network (ANN) under different aspect ratio, thickness of plate, number of pits, crack length, and pit depth over thickness of the plate. Based on the numerical results, in rectngular plates, ultimate strength for pitted plate and cracked-pitted plate are almost the same, while in square plates when degree of pitting is low, negligible effect of longitudinal crack on the ultimate strength is detected. For thin plates, less influence of pit corrosion on ultimate strength reduction is observed in comparison to thick plates. Also, it is found that the arrangements of pits in the cracked-pitted plates on ultimate strength reduction is more influential than number of the pits. Finally, an equation is suggested to predict the ultimate strength of corroded plated with longitudinal crack using ANN's weights and bias.