Residual ultimate strength of hull structures with crack and corrosion damage

Crack and corrosion are two kinds of common damage frequently occurring in marine structures, and therefore it is important to analyze their effect on ship ultimate strength. Two kinds of method are used to analyze the ultimate strength, Nonlinear Finite Element Method (NFEM) and Idealized Structural Element (ISUM), which are validated in this paper by ISSC benchmark container ship subjected to bending moment. Among the common crack types of container ships summarized by IACS, seven representative crack types are chosen to apply on three container ships and analyze their effect on the residual ultimate strength. Based on the numerical results, simple equations are fitted to predict residual ultimate strength of cracked container ship. Considering that there is little corrosion data about actual container ships, the corrosion additions ruled by classification societies ABS, CCS and DNV are seemed as the most serious corrosion and then the corrosion effect on residual ultimate strength is analyzed.