FPSO运动与波浪载荷三维水弹性分析方法研究

3-D hydroelastic method for analysis of motion and wave loads of an FPSO ship

为了与三维水弹性方法相匹配,将二维梁振动理论与三维刚性船体湿表面网格划分方法相结合,提出了一种适用于三维弹性浮体的湿表面网格划分方法.在此基础上利用广义流固耦合界面条件,建立分布源积分方程,获得计及船体弹性效应的三维水动力系数和绕射力.进而建立了船舶在规则波中的广义水弹性运动方程,求解出各阶振动的主坐标后,利用模态叠加法计算船体的波浪载荷.通过实船计算表明,该方法具有较好的计算精度.

A new mesh generation method for 3-D hydro-elastic analysis is proposed which combines the Z-D Timoshenko beam theory and 3-D wetted surface mesh generation methods. On that basis, the integral equations of distribution source using for solving fluid potential were established based on the generalized interface boundary conditions of fluid and structural interactions. Then 3-D hydrodynamic coefficients and diffraction forces were obtained, which took account of elastic effect of hull. Furthermore, generalized hydro-elastic equations of ship motion were setup and the vibrations with respect to various principal coordinates were evaluated, and the wave loads over hull were calculated with modal superposition method. The results for a floating production storage and offloading （FPSO） tanker showed that calculations with the 3-D hydro-elastic analysis method proposed in this paper have high accuracy.