An efficient FEM–BEM coupling method in wave radiation problem analysis of oil platforms with complicated geometry

Abstract Real body model meshing and data preparation on body surface are two critical steps for the sea load calculation using boundary element method. In this study, an efficient procedure to solve these two issues is developed. The FEM type meshing model is used to construct real 3D platforms. Basic parameters such as mass and volume of platform are directly calculated from FEM model. A data extracting algorithm is developed to obtain the necessary data block on body surface of FEM model for the use of BEM method. A Double and Multiple Nodes Relocation Method (D&MNRM) is employed along sharp edges of FEM model to remove geometrical singularity. Based on the newly rearranged boundary information, shallow water Green function and higher-order boundary element method are used to solve the integral equations. A simple example for floating cylinder and a complex example for ETLP are used to validate the added mass and damping. The results show that the proposed method is efficient and can be extended to wave load analysis of any type of platforms with arbitrary shape.

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