Ultimate strength analysis of ships plate due to corrosion

Abstract

Today in maritime industry, it is a mandatory task to compute the ultimate strength of structural components and their system for structural design and strength assessment based on ultimate limit states. Increasing the number of ship failure because of structural incapable to support the load have gain the motivation and interest to study the ultimate strength of the ship’s structure. One of the reason of ship structural failure mainly because of ship’s plate corrosion. Through this thesis, the study have found out that decreasing thickness of the plate due to ship’s plate corrosion will decrease the critical load of the ship’s plate itself. The study concern about compressive uni-axial loading on the ship’s plate which resulting linear and nonlinear buckling effect. The critical load of the ship’s plate structure is study using method eigenvalue linear buckling analysis by ABAQUS Finite Element Software packaged. The result show that more lower the critical load by the structure, more tendency the structure will fail and reach the un-stability mode of deflection. The ultimate compressive strength on the other hand showing the strength of the ship plate under condition of nonlinear buckling analysis. The condition which ship plate located at the bottom and middle section of bulkhead experienced more compressive stress compare to other part in ship. This is according to maximum moment according to shear force-moment diagram of any ship that gives the maximum moment stress at the middle of the ship. Finding ultimate strength of the ship’s plate gives the understanding about the concept of allowable limit load the ship structure can withstand under ship service loading. The parameter of plate slenderness ratio is important for linear and nonlinear ship’s plate buckling analysis and the ultimate strength is calculated based on formula by Faulkner.