Operational Risk Evaluation of Oil Tankers via Multivariate Gaidai Reliability Framework Incorporating Memory Effects

The retreat of Arctic Sea ice may exert a major impact on economy，potentially transforming the nature of commerce between Asia, Europe, and the Americas. Projections indicate a 40% reduction in transit distance and a 30% decrease in voyage time between Europe and northwest Asia compared to traditional routes such as the Suez Canal. However, even during summer navigation, fragmented floating ice persists, generating stochastic ice loads on vessel bows and hulls through complex ship-to-ice interaction. For structural design, statistical extrapolation methods are required to accurately assess excessive areal bow/hull stresses. This study proposes a novel multi-modal structural damage risk assessment framework to evaluate extreme bow areal stresses in oil tanker traversing Arctic routes. The operational hazards assessment was performed in two distinct stages. In the first stage, the vessel areal stress distribution across the oil tanker’s bow/hull was assessed using the ANSYS/LS-DYNA software package. In the second stage, characteristic/design excessive bow/hull stresses were predicted by utilizing multi-modal Gaidai hazards assessment approach, with specified return periods of interest as input parameters. Realistic ice-thickness distributions were incorporated into the model as critical environmental input variables. Vessel routes are strategically selected to exploit ice thinning patterns during specific seasonal navigation windows. A key advantage of the proposed risk assessment methodology lies in its capacity to evaluate dynamic system risks for high-dimensional system with theoretically unbounded component interactions. This study aims to propose and validate a novel multi-modal Gaidai hazards assessment methodology for quantifying extreme bow/hull stresses in oil-tanker operating on Arctic routes.