Stress concentration at outlets

[Anonymous]

I have been getting high stress concentrations at the outlets of multiple models when applying internal pressure. I have tried creating assemblies using custom parts that I have made, parts downloaded directly from the content center, and even a single tee which was downloaded from the content center.  When I apply pressure to the internal faces there are very high stress concentrations at the bend of the outlet. I have tried filleting the internal bend to reduce the effects and also splitting the part around the outlet but haven't had any luck. Adjusting the mesh size only seems to increase the stress at these points. Attached are screenshots of the Tee from content center with pressure applied to the internal faces. The part is constrained on each side of the run and the branch is the outlet mentioned above. Am I applying these loads incorrectly or is there any way to remove these stress concentrations?

[JDMather]

Attach file.

[Anonymous]

Attached.

[johnsonshiue]

Hi! I am not surprised with the result. Rounding the sharp edges do help dampen the stress concentration. What is unrealistic here is the pressure load. The pressure may approach constant at the big tube. But, it should gradually decrease when approaching the outlet. You should not use constant pressure. The outlet area is probably somewhere between the tube pressure and the ambient pressure. Also you need to apply ambient pressure on the outside of the tube. Otherwise, the fitting would be operating in a vacuum.

Many thanks!

[JDMather]

I am thinking that you are after the Hoop Stress, but I have not seen a good discussion on this topic here.

See the two studies in the file that I attached.  (When you open the file - it will appear as though there is no geometry - but go into the simulation environment.)

I set Frictionless constraints on the sections of pipe and Detect and Eliminate Rigid Body Modes (motion) for static analysis.