Methodology of evaluating local dynamic response of a hull structure subjected to slamming loads in extreme sea

This paper presents a methodology to study the local dynamic response of a 21kTEU container ship under extreme impact load. The extreme impact velocity was analyzed by long-short term analysis and the time history of impact velocity was obtained by seakeeping analysis. The structural response was carried out based on uncoupled computational fluid dynamics (CFD) and finite element analysis (FEA). The CFD method in Fluent was used to predict the impact load through simulating the water entry. The dynamic response of a bow structure was evaluated by nonlinear finite element analysis in Ls-dyna. A block method was introduced to treat the fluid-solid interface. The temporal and spatial characteristics of the impact pressure were discussed showing that the impact pressure is greater when the impact position is close to the forward perpendicular and the upper deck. Nonlinear dynamic characteristics including deformation and Von Mises stress were presented. Attention should be paid to the deformation in the middle of the bow and the stress in the reinforcing bars and plates in the structural design. This methodology can provide guidance for predicting and improving the carrying capacity of ships under impact pressure.

Automated summary

The study analyzes the extreme impact velocity and impact pressure time history, structural response, and dynamic characteristics, finding that impact pressure is greater when the impact position is closer to the bow and upper deck. Attention is drawn to deformation and stress distribution in structural design, with the methodology offering guidance for predicting and improving the carrying capacity of ships under impact pressure.