腐食ピットが発生している構造部材の等価板厚評価に関する研究

抄録

Pitting corrosion is a great concern when the integrity of ship's hull structures is considered. Corrosion pits with a conical shape are typically observed on coated hold frames in way of cargo holds of bulk carriers which exclusively carry coal and iron ore. In the present study, a series of non-linear FE-analyses has been conducted to investigate the effect of such pitting corrosion on local strength of hold frames using various structural models, that is, collapse models accompanying no buckling, lateral-torsional buckling models, local buckling models, shear buckling models and web crippling models. It has been revealed that the ultimate strength obtained in the present analyses for all the structural models except shear buckling models could be well predicted by the empirical formula, which was developed in the previous study to estimate the ultimate strength of steel plates under compression and shear. In the case of shear buckling models, it depends on the web thickness whether the empirical formula could be applied or not.