A Study On Fluid-solid Coupling Simulation Of Offshore Platform Pile Foundation Structure

Under the environment of ocean waves, The offshore and Marine engineering structure is often subjected to wind, wave, current, among them the wave load is the main controlling one. In port and offshore engineering, pile and pile group are the most structural form. The research on pile structure under the wave load, hydro-load and its effect on the wave field is increasingly becoming an important problem in fluid mechanics. Therefore, simulation analysis of two-way fluid-structure interaction for the wave field and pile structure has a profound research significance.This paper made a briefly introduction of ocean energy development in China, summarized the calculating methods about interaction of wave and marine structures, summed the research progress of wave numerical simulation,as well as advances in fluid-solid coupling research. The control equations, the turbulence model system and other basic principle related to fluid-structure coupling analysis were discussed, and made a systematic overview of the linear potter, control equations and boundary conditions.There was a briefly introduction on the method of numerical wave, and adopted VOF method to realized the setting of moisture free surface. ANSYS Workbench and CFX software were used to realised3-d numerical wave flume, by setting the boundary conditions, three dimensional numerical wave was determined; for more the availability of the numerical model was verified. Secondly, ANSYS and CFX were used to simulate one-way (two-way) fluid-solid coupling between single pile and wave field. For result analysis of the two simulation methods, maximum equivalent stress of pile and the variation of flow field was made respectively, as well as evaluated the stability of the pile. Finally ANSYS and CFX software were used to simulate two-way fluid-structure interaction for tandem double piles and wave field, integrated with the simulation results of the single pile, the maximum equivalent stress of both were compared.The results show that:the maximum stress occured at the bottom of the pile, and stress value was between15704pa-16320pa and occured periodical variation. According to the Von Mises yield criterion, this mean that the pile is stable under such condition of the wave; Two-way fluid-structure interaction has advantage on closely simulate the real state. The maximum equivalent stress on single pile and double piles were analyzed. The maximum Von Mises stress of Tandem double piles was smaller than the single pile’s.In this paper, research on fluid-structure coupling method for single pile and double piles has certain reference value.