Study on the Effect of Climate Change on Ship Responses Based on Nonlinear Simulations

Hull girder ultimate strength, which governs sagging and hogging failures, is one of the most critical failure modes for a ship hull. The Structural Reliability Analysis (SRA) methodology has been used to develop Common Structural Rules (CRS) for tankers and bulk carriers. A linear model for bending moment in extreme weather with a nonlinear correction factor has been adopted in the analysis. It is difficult to conclude on the model uncertainty associated with nonlinear effects of bending moment as, until now, there are very limited studies addressing this topic. In this paper, the nonlinear effect on ship responses will be analyzed, and the potential effect of climate change on ship responses will be investigated with the improved 3D Rankine Panel method using nonlinear wave input. The nonlinear wave input is generated by the HOSM (Higher order Spectral Method) wave model incorporating higher order nonlinear effects, including nonlinear free-wave modulation as well as higher order bound harmonics. The North Atlantic past and projected future wave climates are considered.