Shell Loading
Shell Loading
(OP)
Is anyone aware of an analytical (non-FEA) solution of how to calculate the allowable forces and or moments that can be imposed on a roof manway of an API 650 oil storage tank? The roof is a self supporting cone design, and the manway is not located in the center of the roof. I think the failure mechanism would be local buckling of the roof plates, due to the compressive loading, large (local) radius of curvature, and thinness of the roof plates. Any help would be greatly appreciated. I’d even settle for the double infinite Fourier series type of solution that is common in analytical plate/shell mechanics.





RE: Shell Loading
RE: Shell Loading
RE: Shell Loading
However the self supported cone roof of an API 650 tank is normally much closer to a flat plate than to a cylinder, so I'm afraid WRC297 is not very suitable.
As far as the bending moments on the manway are concerned I would suggest the use of trunnion formulae you can find in the Roark (Flat Plates chapter).
For the axial load I can't find a specific suggestion. By the way this type of structure will support only a very limited axial load. I suggest that the value is the allowable (live load + dead load) insisting on nozzle, that load being determined with the formula applicable to self supported cone roofs using the actual thickness, provided a reinforcing plate of area equivalent to the nozzle opening is used.
I'm afraid this is not very useful, but I can't find a simple method to prove any higher resistance (and wonder if a much higher resistance would be calculated by a detailed analysis).
prex
motori@xcalcsREMOVE.com
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