Hull Structural Safety Assessment -of Aged Non-ice Class Container Vessels -in an Arctic Operation

Abstract

Within the industries development, the situation of melting ice in Arctic Ocean become more disastrously and the global warming phenomenon affect the temperature to induce the sea level increasing. For these reasons that the undiscovered nature resource and route of operating in Arctic Ocean can be used more sufficiently at present. Nowadays, the ship industry try to find the way to operating in Northern Sea Routes (NSR) which has lower fuel wastage and shorter time of passing through the Arctic Ocean rather than south one. But the existing iced class ship is in short supply, and each construction time of new iced class ship proceed long time, therefore ship owners would like to understand the structure strengths of aged non-iced class container ships when operating in Arctic Ocean. To evaluate the safety of large container hull structures under low temperatures, the priority issues are ultimate and fracture strengths. Especially after the MOL accident, it gave a rise to concentrate the ultimate strength problem of ultra-large vessels. As well as the impact damage of hull structures in ship collision will induce environment catastrophe and cargo loss. Different from previous studies for ultimate strengths which focused on the low temperature or aged plates separately, under the realistic situation that both need to be as references. Consequently, both corrosion of aged ship structures and low temperature effect were undertaken as a main factors for ultimate strength analysis in this paper. The ultimate strengths were estimated by Maestro software with the idealized structural unit method (ISUM) which verified stiffened panels for different locations and hull girder structures applied on a 13,000 TEU container ship. Furthermore, the fracture effect and structure resistance according to low temperatures were estimated by nonlinear dynamics impact analysis with LS-DYNA code.