Comparative study of ultimate hull girder strength of large double hull tankers

A systematic study of theoretical methods for predicting the ultimate hull girder strength of ships is carried out based on long-time theoretical and experimental work in authors group. An integrated framework of non-linear finite element analysis, a locally improved idealized structural unit method (ISUM), a simplified method (SM) in which average stress-strain relationship is derived using beam-column theory, along with an advanced analytical method (AM) which is coupled with an elastic-plastic method (EPM which is a combination of elastic large deflection analysis and rigid plastic analysis) of ultimate buckling strength of stiffened panels and suitable for biaxial bending and non-symmetric structures of damaged ship hulls, are used to perform a comparative study of ultimate hull girder strength of a 300,000 dwt large double hull tanker. The calculation results are also compared with single step procedure of common structural rules (CSR) for double hull tankers and comparative analysis of calculation methods of ultimate hull girder strength is carried out in many ways.