A recent debate came up between a friend and I regarding whether it is considered double dipping to computer nozzle flexibilities with an FEA program such as NozzlePro, and then in CAESAR also model the vessel itself as a piece of pipe to simulate the flexibility of the vessel.

I argue that it is not double dipping, my coworker says it is, since you specify a length and end condition in NozzlePro that affects your nozzle flexs.

My reasoning is that the FEA calulates LOCAL nozzle flexs, based on where it is located on the vessel, but you can still model your vessel as a piece of pipe in CAESAR. My coworker only uses rigid elements to model equipment, and assigns flexibilities at the nozzle-shell junction.

What says you all? Any professional opinions?