There are limits that must be satisfied before SIFs can be calculated on trunnions. These limits come directly from the paper by Hankinson, Budlong and Albano.
t/T ≥ 0.2 and t/T ≤ 2.0
D/T ≥ 20 and D/T ≤ 60
d/D ≥ 0.3 and d/D ≤ 0.8
Where:
t = Wall thickness of the trunnion
T = Wall thickness of the bend
d = Outside diameter of the trunnion
D = Outside diameter of the bend
To review the SIFs for a bend that does not have a trunnion, do not enter values for the trunnion-related input fields on the Trunnion tab.