Water storage tanks are widely used in the nuclear industry for safety purposes, chemical water control and primary volume water management. Under seismic load, the sloshing of water inside the storage tank can cause a strong dynamic response, which may also change some mechanical characteristics of the tank, for example the center of mass. The water sloshing analysis is therefore an important part of the modal and seismic analysis of water storage tank. However, the water sloshing effect contains a complicated fluid-structure interaction but structural analysts cannot afford the time to spend on the calculation. It is important to build up a simplified equivalent model for the simulation.
EDF has been developing since 1989 its own in-house FEA code baptized code_aster, which is included in the SALOME-MECA mechanical package. In this paper two simplified fluid-structure interaction models are performed using SALOME-MECA. Firstly, an optimized Housner model is derived with formula and implemented with 3D finite model. Additionally, another 3D finite element model using added mass model assembled in code_aster, which can simulate more precisely the fluid-structure interaction of the water storage tank.
Based on the theory of these two models, their natural modes results and seismic response results are carefully compared and analyzed. The results indicate Housner model can provide a precise value of the water sloshing frequency and its displacement value is not accurate enough due to the impulse mass and convection mass simplification. However, the added mass model in SALOME-MECA can provide a more accurate and reasonable result on vibration mode calculation, which may provide an interesting alternative method for seismic verification for the nuclear refueling water tank.