Hull girder ultimate strength assessment according to rules requirements

Residual ultimate strength of hull girder is rather important in naval vessel design, being a fundamental driver and a specific project requirement. In this paper, an applicable approach facing such challenge in pre-liminary naval vessel design is presented in the form of a benchmark study. Two typical case-studies were defined and three damaged positions along the hull length were analysed at different transverse section heights as required by class rules. First case aims at comparing notation requirements provided by Lloyd’s Register and RINA Naval Ship Rules using the same input threat. Second application focuses on results ob-tained by different class support software using damage extent and load conditions defined by Lloyd’s Regis-ter Rules as a baseline. Results of residual ultimate strength analysis of damaged hull girder in all considered cases are outlined and compared, also including results of direct, residual strength, elastoplastic analyses performed by finite element software.