FEA Considering Piping Loads

[UKEng157]

Good morning everyone,

I have a current piping system which requires verification by FEA (a small area of a tee has thinned, which cannot be assessed within the piping software).

I have searched on here and elsewhere online, however I cannot find a recognised/accepted method of transferring the loads from the piping software to the FEA.

If I transfer the piping loads to all three piping ends (2 x header and 1 x branch), the model will be unrestrained. I am aware that weak springs can be used to stabilise the model, however the model is not balanced, and so the model is not stable. I have also tried applying displacements, which works OK for a linear elastic model, however should not be applied when carrying out an elastic-plastic analysis.

Does anyone have any ideas or recommendations?

Cheers

 

[FEA way]

Large pipe systems are rarely analyzed with FEA. Usually only a small segment (such as junction or valve) is subjected to stress analysis in FEA software. However, some programs (such as Abaqus) even offer special elements called pipe and elbow elements meant for such simulations (for example analyses of buried pipelines).

When it comes to constraints, you could make use of symmetry or (that’s the most common approach) simply fix the selected pipe segment away from the region of interest. For example cut some part of the pipe including junction and then fix ends of these pipes away from the junction to reduce or eliminate the influence of constraints on the stress in analyzed connection.

 

[goutam_freelance]

In the piping software incorporate 3 nodes reasonably close to the T point and get the nodal loads for 3 points. Now in FEA input the geometry and other data up to these 3 nodes. Fix any one of the 3 nodes and input the nodal loads for other 2 points at the ends. From static equilibrium the nodal load for the 3rd node(fixed) will automatically be equal to the piping analysis output value. Now your model will not have any unrestrained DOF.

Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/