

The composite nature of laminates used as a primary structural material for the tank necessitated the use of 2D Shell elements. Therefore, the mid-surfaces were extracted from the solid CAD model provided and the pump ducts were removed from the geometry.
The use of the Shell Element is appropriate in this application as the various layers of the laminate can be characterized. It is also a good approximation as the thicknesses of the laminates are small relative to the general size of the individual components. Consequently, by selecting a Shell Element in Patran / Nastran, it was possible to model each layers of the laminates accurately.



For the purpose of this static analysis, an amalgam of loads was considered including South East winds of 31.5m/s, a current of 1.1m/s, wind load on handrails, wind on nets (Jump Net, Outer Walkway Nets, Bird Lid Net). Also taken into account were the effects of buoyancy from the multiple bodies constituting the tank assembly. Finally, mooring loads and a dummy load applied to the tank drain were also prescribed to the model.
Since water level inside the tank is quite close to the outside water level, the hydrostatic pressure induced on the various bodies is fairly small. Under steady state conditions, the buoyant equilibrium is reached when the water level inside the tank reaches approximately 7.6m. The head experienced by the walls and the bottom floor under this condition is solely the differential level between the inside and outside water level. Consequently, a 1’ head was assumed present at all times inside the tank.
| Component | Location | Type of Load (Wind S-E and Current N-W) | Magnitude | Direction |
| Deck Platform 1-24 | Upper Surface Corners | Moment ^ to S-E Direction | 200N·m | ^ to S-E |
| Deck Platform 1-24 | Upper Surface Corners | Force | 187,5N | S-E |
| Deck Platform 1-24 | Inner Upper Surface Corners | Moment ^ to S-E Direction | 2222 N·m | ^ to S-E |
| Deck Platform 1-24 | Inner Upper Surface Corners | Force | 2083N | S-E |
| Deck Platform 8-20 | Freeboard (Outter vertical Wall) | Distributed Force on all Surfaces | 63740N | S-E |
| Sidewall 1-7, 21-24 | Outer Wall | Distributed Force on all 12 Surfaces | 150000N | N-W |
| Sidewall 1-24 | Outer Wall | Buoyancy Force on outer Shell | 442N | Up |
| Sidewall 1-24 | Inner Wall | Hydrostatic Head | 2.98 Pa | Normal |
| Bottom Floor 1-24 | Bottom Surface | Buoyancy Force on all 24 surfaces | 228N | N-W |
| Bottom Floor 1-24 | Central Drain | Suction Pump | 10000N | Down |
| Bottom Floor 1-24 | Bottom Surface | Hydrostatic Head | 2.98Pa | Normal |



