3-D Hydro-elastic Analysis Method Of Ship Motion And Wave Loads On FPSO Tanker

The accurate prediction of wave loads is a key factor of design and strength evaluation for ocean engineering structures. Till now, strip method and 3-D method based on rigid model have been broadly utilized in the engineering practice. But both of them still have certain disadvantages while handling the flexible effect of large ships or the ocean engineering structures. A 3-D hydro-elastic analysis method for wave loads of FPSO which has enough engineering accuracy is studied in this paper. Through the comparison with 3-D rigid method, the engineering practicability of 3-D hydro-elastic is investigated.Firstly, a new mesh generation method for 3-D hydro-elastic analysis is proposed with the combination of 2-D Timoshenko beam theory and 3-D wetted surface mesh generation method. It is proved that this method has a characteristic of good accuracy, high efficiency and flexibility.Secondly, the author gives a detailed statement of the 3-D rigid wave loads calculation method. The motions and wave loads of a FPSO predicted by this method are compared with those given by the software SESAM developed by DNV classification society. The comparison shows that the results between them are close to each other.Thirdly, the source distribution integral equations for solving fluid potential are founded based on generalized interface boundary conditions of fluid and structure interactions. The 3-D hydrodynamic coefficients and diffraction forces is obtained considering flexible effects of hull. Then, hydro-elastic equations of ship motions are founded and the principal coordinates are obtained. Modal superposition method is used to calculate wave loads of hull based on the principal coordinate responses.At last, the 3-D hydro-elastic method is compared with the 3-D rigid method taking the YOUYI FPSO tankers as an example. The results shows that the 3-D...