ABSTRACT
Quasi-static indentation tests using two types of large-scale structural models simulating ship collisions were carried out to study whether HDS (highly ductile steel) increases a ship’s crashworthiness. The large-scale structural model represents a part of the side shell of a very large crude-oil carrier (VLCC) at half its true scale. One model used HDS and the other model used conventional steel. In the test involving conventional steel, cracks initiated at the weld toes of the stiffeners at the time of the indentation displacement was about 150 mm. The cracks largely occurred at the end of the test. On the other hand, in the test using HDS, no significant fracture occurred even though the test continued until the indention displacement was about 240 mm. The crack initiation positions in the experiments agreed with the position of the maximum equivalent plastic strain identified by elasto-plastic finite element method simulations with solid elements on the structural model indentation tests. The effect of HDS on the increase in crashworthiness as well as its role in the prevention of crack initiation in the case of out-of-plane deformations was demonstrated.
