Ultimate Strength Analysis Of Ship Structure Based On Idealized Structural Unit Method

The ultimate strength of ship structures indicates the limits of ship's carrying capacity.It has always been widespread concerned in the field of the ship mechanics. Through years of development, there are many theories of hull ultimate strength calculation. Ideal structural unit method (ISUM) is one kind of the theories.Compared to other theories, ISUM has advantages in time running, high ccuracy and so on. Based on the ideal structural unit method, the ultimate strength of hull structure will be analyzed in this thesis.Based on the theory of the ideal structure element, three basic elements for analyzing ship hull ultimate strength are listed in the thesis:idealized beam elements, idealized rectangular plate elements and idealized stiffened plate element. Stiffness of the three elements and the detailed derivation of the formula are given in the thesis.Through the establishment of various failure modes of the element stiffness matrix, calculation program for the analysis of ship hull structure ultimate strength is compiled;and the impact on results is explored about the modeling way of different structural units.A series of typical box beam model, including oil tankers and bulk carriers are taken as examples In the end,a set of effective ultimate strength of ship structure calculation simplified method is given.The program solution is compared with the experimental results and the finite element solutions. Considering the program's accuracy, time consuming, modeling work and other factors, it fully demonstrates the program's reliability, simplicity and rapidity.So this method can be used in ship's ultimate strength check and evaluation. By sensitivity calculation, analysing the influence of ultimate strength of the several main parameters quantitatively, the ultimate strength of these parameters on the sensitivity are researched.It can be as the further reference.for the hull structure design.