Affiliations: Centre for Marine Technology and Engineering, Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal | Technical University of Varna, Varna, Bulgaria | University of Newcastle, Newcastle, UK | Technical University of Szczecin, Szczecin, Poland | University “Dunarea de Jos” of Galati, Galati, Romania | Principia Marine, France | University of Liége, Liége, Belgium | National Technical University of Athens, Athens, Greece
Abstract: The objective of the paper is to evaluate the ability of simplified structural analysis methods, based on the Smith formulation to predict the ultimate strength of a damaged ship. Such methods are now widely accepted as a reliable and fast way to obtain the longitudinal strength of an intact ship. In order to extend these methods to damaged ships, first a benchmark study on the intact ship was performed in order for the differences between the methods to be evaluated. Afterwards the methods are applied to the same ship section but with damage, which was defined by removing the structural elements from the affected areas. These, in turn, were obtained from a previous study in which a collision was simulated using a finite element model. Results obtained for the ultimate strength were compared against each other and with the results of the finite element analysis. Aside from some exceptions, the results of the approximate methods agreed well with each other for the intact and damaged conditions. The simplified methods are more conservative than the finite element analysis in hogging while they seem to give a very good approximation to the result for sagging with some of them overestimating this value.
Keywords: Ultimate strength, damaged hull girder, Smith method, longitudinal strength, vertical bending moment
