Ultimate strength characteristics of as-built ultra-large containership hull structures under combined vertical bending and torsion

The aim of the present paper is to investigate the ultimate strength characteristics of as-built ultra-large containership hull structures under combined vertical bending and torsional moments with varying the ship size. The intelligent supersize finite element method (ISFEM) is employed for the ultimate hull girder strength analyses. A total of three as-built containerships carrying 9300 TEU, 13,000 TEU, and 22,000 TEU are studied. Based on the computations, ultimate strength interaction relationships of containership hull girders under combined vertical bending and torsional moments are also formulated by a curve fitting. Insights and structural design recommendations obtained from the study are summarised, which will be useful to not only enhance the ultimate limit state capacity of containership hull structures in existing sizes but also achieve the robust structural design of ultra-larger containerships which have never been built before.