The Study Of Ultimate Strength Of Semi-submersible Platform Based On Non-linear Finite Element Method

It is necessary to study the ultimate strength of Semi-submersible platform in order to ensure the safety of the structure. Based on NFEM, a modified RIKS algorithm is used in this paper to study the ultimate strength of a series of structures of the Semi-submersible platform. At the same time, the key techniques of the global ultimate strength of the semi-submersible platform also have been investigated. The major works are as follows:1. The ultimate states of the semi-submersible platform are introduced, a variety of dangerous structures of semi-submersible platform under the ultimate state are summarized and the position of the dangerous structures is established through the strength calculation.2. The origin of the nonlinear finite element problem and the arch-length method which is used to solve the nonlinear finite element problem are introduced. The method is applied to box-shaped girders, and then the feasibility of the method is checked.3. The ultimate strength of a series of structures of Semi-submersible platform is studied. Through A large magnitude of calculation, the principles of parameters which affect the local structures of Semi-submersible platform are presented.4. The global ultimate strength of the semi-submersible platform is pre-evaluated, the ultimate loads which the platform is capable to sustain are established under the ultimate states and the Wave Parameters can be derived.