Hi all,

I'm modelling a vessel as described in the Chapter 3 (page 3-9) of the Caesar Application Guide; I've some doubt:

first point: the example says "Define a unique vessel node on the nozzle spreadsheet." On the example is the 240?

second point: if the nozzle defined is the 240 should I use the local forces at this point for the nozzle verify using WRC 297?

third point: are the element 340-345 and 345-350 rigid or not? what's the difference? modelling that elements as rigids (zero weight) I don't consider the weight of the vessel on the base anchor, am I right??

Last point: what't the main differnce between node 240 and node 140?


TY.

Any comment?

You don't make it easy.
It appears to me that you are referencing page 25 of the current Application Guide.
first point: yes
second point: yes, but it would be simpler to collect these local forces and moments from the restraint report. CAESAR II will list node 240 there. Think of this as a relative restraint (between 140 and 240).
third point: weight is not the concern here, stiffness is. I think it poor modeling practice to allow this single nozzle to push the vessel around. A stiffer vessel model would be more conservative (with respect to the pipe). You don't have enough information here to develop the total weight on the vessel foundation - that's not the issue here.
last point: don't think of 140 and 240 as being two discrete points. Instead, think of them as a pair of points that consider the flexibility of the vessel shell around the nozzle. They occupy the same point in space and they are related to one another by the calculated flexibilities.

Thank you Dave, your answers are always very useful.