A method based on non-linear FEM for ultimate limit state assessment of ship hull girders

In this paper, a refined method for ultimate limit state assessment of ship hull girders based on non-linear finite element method is proposed. Commercial finite element analysis codes ANSYS and MSC.MARC are used to established the model and analyze the large elastoplastic deformation respectively. Firstly, the initial deflections and welding residual stresses of steel structures are considered and calculated. Secondly, the sensitivity factors of ultimate limit state are analyzed by taking box-girder, four classic-type seagoing ships and one standardtype inland-water ship as a benchmark study. Finally, the accuracy and applicability of the method in present study are presented and discussed by comparing with the results from other methods. The method is considered to be useful for ultimate limit state assessment of ship hull girders, which will promote the introduction of ultimate strength criterion to the design rules for seagoing ship or inland water ship in a sense.