PRESSURE-IMPULSE DIAGRAM FOR PREDICTION OF STRUCTURAL DAMAGE TO THE LNG FPSO TANKS UNDER SLOSHING IMPACT LOADS

摘要

Sloshing impact loads can cause severe structural damage of cargo tanks in LNG-FPSOs (FLNGs). Sloshing studies can be classified into two groups, namely hydrodynamics- and structural mechanics-related studies. The present study is a sequel to the authors’ previous papers [1-2] while it is mainly related to the structural mechanics. In the present paper, the new method for probabilistic sloshing assessment previously developed by the authors is briefly addressed. The nonlinear impact structural response characteristics under sloshing impact loads are examined by the nonlinear finite element ANSYS/LS-DYNA method. An ISO-damage curve representing the pressure-impulse diagram is derived for self-supporting prismatic shape LNG cargo containment system of a hypothetical FLNG. The insights developed from the present work can be useful for damage-tolerant design of cargo tanks in FLNGs.