Study on the Standardized Nonlinear Finite Element Analysis of the Ultimate Strength of Ship Hull Girder

The ultimate strength of ship hull girder has been a study hot spot in ship mechanics. Caldwell method, Smith method, idealized structural unit method and nonlinear finite element method are usually used to predict the ultimate strength of ship hull girder. In the paper, a standardized procedure on the nonlinear finite element analysis of the ultimate strength of ship hull girder is presented. Firstly, the finite element modeling for the ultimate strength of ship hull girder is studied, which include material property, element type, mesh size, model length and boundary conditions. Then, the influence of welding residual stress and initial deflection are studied. For the validation of the method in this paper, a MST-3 model from the test of Nishihara is used as an example. Finally, the results from the nonlinear finite element analysis and Smith method are compared for the ultimate strength analysis of a container ship. The study shows the standardized procedure on the nonlinear finite element analysis of the ultimate strength of ship hull girder is satisfactory and suitable for engineering application.