In order to identify the change in structural strength after an interaction between hull girders and ice, this paper puts forward an analytical technique which can determine the structural strength of hull girders after an ice riding accident and disclose the related structural strength features.

First, the hull girder structural strength analysis model and associated load analysis model are constructed in accor-dance with the characteristics of each section. To account for the buoyancy variations brought on by ice riding, the buoyancy distribution of the ice riding conditions is retrieved from the load analysis model and inserted into the structural strength analysis model. Gravity and the reaction force of the ice are then used to determine the structural strength. Finally, an analysis is carried out on the impact of lifting position and height on the buoyancy, shear force, bending moment and local stress distribution of the hull girders.

The re-sults show that the sites of buoyancy and shear force of the hull girders are situated in the stern part and middle part, and unaffected by changes in the bow lifting height. The shell is closer to the vertical when the lifting position is at the bow of the bulbous bow, making it harder to resist the ice lever support reaction and resulting in the high stress areas becoming comparably larger and more dangerous.

The proposed technique has high computation efficiency and can be used to estimate how hull girders will respond to a signi-ficant bow lift and make preliminary judgments on hull girder construction strength under risky ice riding conditions.