Shaun,
Thank you for the response.
As for looking at the part and ignoring the thread as a failure point, my company uses a separate thread calculator to determine when the thread would fail. This is why I am not considering it as a failure point. I will also be the first to admit that I am not the best with FEA and I try and keep things as simple as possible. If things get complicated, I do not trust myself to get accurate results. The part shown here is more or less a basic cylinder. As far as my constraint adding stiffness to the part elsewhere, I agree, that is something that I want to avoid. I know the way I am fully constraining it right now is not the best way, but I was not sure how else to simulate threads holding the part in place on both ends.
When I say that I'm ignoring the high stress areas, I mean that if I get a high stress concentration, I will ignore those results. They still happen, but when I present my results I classify them as outliers. I know this is not the failure point that I am analyzing, I am looking at the thin wall sections of the part. I am performing the FEA to prove hand (and by hand I mean excel) burst/collapse formulas. The hand calculations are not able to account for cutouts, and this is where the FEA can provide more accurate information about whether a part can withstand a pressure or not. Again, I am trying to keep it as simple as possible. I would rather not remove entire volume regions from the end result picture.
Because my model is a cylinder, i can use symmetry. I am currently using half symmetry.
I will experiment with weighted links to see if i can remove the singularities. I will also experiment with having only axial constrained and allowing radial/theta movement. Thanks for the help.
-Andrew