The aim of the present paper is to investigate the ultimate strength assessment method of stiffened plates with grooving corrosion damage under uniaxial compression. A series of nonlinear finite element analyses has been conducted to investigate the effect of grooving corrosion, including the depth and width of corrosion, the location of corrosion and the ratio of the corroded volume loss of stiffener to that of plate. Based on the relative parameters (such as slenderness of the stiffened plate, aspect of the plate) examined to determine the influences of the stiffened plates on the ultimate strength, the ultimate strength reduction formula of stiffened plates subjected to weld-induced grooving corrosion was derived by data analyses. Research shows, this derived formula can be used to evaluate the ultimate strength of stiffened plates with grooving corrosion.
Worldwide, aging of ships is increasingly serious and ships are in a high salinity environment for a long time, so hull structures are at high risk of corrosion during ship service. Corrosion is the chemical reaction of metal to its surrounding environment, and it would lead to degradation of performance of the hull structure, such as the ultimate strength, operational life-span of ship, the navigation safety, etc. Therefore, evaluating the ultimate strength of corroded marine structures plays a critical role during ship service.
Corrosion is mainly divided into general corrosion and local corrosion and local corrosion is divided into pitting corrosion and grooving corrosion, viewed from the point of the ship corrosion form. Uniform corrosion occurs on the surface of the entire structure, resulting in a uniform reduction of the metal thickness. Pitting corrosion, where there is many pits with different depth, occurs on the local area while the rest of the area does not corrode or slightly corrode. Groove corrosion normally takes place adjacent to welds and is of particular concern for the connection of side frames to shell plate in single skin bulk carriers. So far, the study of the effects of uniform corrosion and pitting corrosion on the ultimate strength of hull structures is relatively mature. but there are still many problems to be solved for the influence of grooving corrosion on the structural strength.