An advanced technique to adjust hull girder load: Part 2 = Application to ship's hull for verification

In this study (Part 2), the technique proposed in the previous study (Part 1) for effectively adjusting the loads on ships and ship-shaped offshore structures was applied to a real ship to examine its usefulness. Various models and boundary conditions for container ships were created, and the hull girder loads were adjusted to target values using the proposed method. The whole ship model, forebody, aftbody and cargo hold model were used as models, and free, cantilevered, and simple support conditions were applied as boundary conditions. All six components of the hull girder load were adjusted for each station: Axial force (AF), Vertical shear force (VSF), Horizontal shear force (HSF), Torsional moment (TM), Vertical bending moment (VBM), and Horizontal bending moment (HBM). To verify the results of the hull girder load adjustment, the adjusted load was integrated or the stress resulting from the structural analysis was integrated and compared with the target value. The proposed method was verified by generating loads that are almost identical to the target hull girder loads for various models and boundary conditions. Since the analysis results may differ depending on the load distribution shape even if the adjusted hull girder load is the same, discussions were held on how to distribute the load. Distributing force vectors directly to nodes is classified as using force fields, while distributing force vectors using stresses and element areas is classified as using stress fields. The existing quadratic programming (QP) method uses force fields, while the proposed method uses stress fields to distribute the load. For each method, a new formula was derived by combining the other's fields, and the hull girder load could be adjusted in a total of four cases. These cases were compared in terms of load distribution and analysis results.