Piping System Pressure Loading

[TyphoonRising]

When modelling a sub-section of piping system with pressure loads, is it standard practice to "close" the ends of the pipes and apply pressure also to these dummy elements? (2D Shell Elements)

This has been a source of great discussion between my colleagues and I.
While I agree that it may not be necessary in a simple straight section of pipe (as each end reacts the other...) if there where bends or change in diameter in the pipe, it would generate an imbalanced load.

These assumptions are of course for steady state, the purpose of the pipe is to supply something.

If the first question were valid, Does anyone agree that applying a reduced pressure on the "working end" of the pipework on the dummy elements that is equivalent to the pressure drop across the system would be appropriate to calculate the "kick load" as a result of the operation. (like the garden hose moving around by itself when it is on and let go, when it is turned off, it stays still)

Thanks for your ideas in advance...

Chris

 

[TGS4]

The term that you are looking for is "pressure thrust", and yes it is required to ensure that the accurate longitudinal stress is simulated. It can be applied as a force or pressure on the end without needing to use dummy elements.

In general, since we would be performing an analysis for design conditions, it is typical that the pressure be uniform and not consider any pressure drop due to flow. if the purpose of your analysis is different, then you need to do what is appropriate.

 

[TyphoonRising]

Thanks for the confirmation.

 

[ShellsPlatesMeshes]

There is an example of similar nature, with some discussion and diagrams on the following Webpage (you may find it useful for the discussion with the colleagues):

http://members.ozemail.com.au/~comecau/quad_shell.htm

(The example is on the bottom of the page; just scroll down.)
Hope this helps.