A study on hull girder longitudinal strength prediction by adopting the accurate plate-combination model based on load-shortening curve

In this study, a plate combination model (PC model) was proposed for evaluating the longitudinal strength of the hull girder. There are representative models such as the PSC (Plate-stiffener combination model) and PSS (Plate-stiffener separation model) models for separating the structural components of the midship sections of hull girder. However, both the PSC and PSS models that are subjected to compressive loads have limitations in accurately considering local structural failure mechanisms. To overcome this limitation, the PC model introduced in this study separates all structural components comprising the hull into the concept of plates. Assumptions were made regarding the boundary conditions corresponding to the PC model to account for welding effects and collapse modes. Based on four assumed PC models, the longitudinal strength of the Dow 1/3 frigate model was compared. The results allowed for the selection of the optimised PC model. This study confirmed that CSR-H method could not adequately consider local collapse. The proposed method can be beneficial for the robust design of ship structures.