Strange B31J SIF values in ROHR2

[claudio_mend]

Good afternoon,
I am modeling a RFT (Reinforced fabricated tee) for a header with NPS36 (914.4mm OD and 9.52mm thick) with a branch that is NPS24 (609.6mm OD and 9.52mm thick) and a reinforced pad of 18mm, as seen on the image below.

RFT-input.PNG

The SIF values given by rohr2 seem a bit strange, especially for the out-of-plane branch SIF. It is showing 11.98 when I was expecting a value of 8.7 according to the equations. As can be seen below:

SIF-RFT.PNG

I checked the calculations using the software PRGIK from Paulin Research group and found a value close to the equations as can be seen below:

PRGIK_SIF-values.PNG

can you tell me if I am doing something wrong?

[rohr2support]

Hi

When you compared the SIFs, did you check that you entered the same thickness of the pad?
If you look at the Rohr2 graphic, tH is the thickness of the pipe with reinforcement.
So in your case 18mm means 9mm of pipe and 9mm of pad.

TTV_thickness.PNG

When you checked the calculation with the other tool, you entered 18mm pad thickness.
So if you want to do 9mm of pipe + 18mm of pad that would be tH=27mm.
And if you enter tH=27mm you get these SIFs in ROHR2.

TTV_SIF.PNG

Best regards

ROHR2 Support

[claudio_mend]

Thank you very much!