1) Try allocating more RAM to CAESAR II (via the Configuration).

2) The SIFs are computed from the equations found in Appendix D of B31.1/B31.3 (or a similar section in whatever Code you're running). Find the equation used for the bend and play with it in Excel to see what you need to do to lower the value. Chances are you won't be able to lower it that much, so you'll have to re-evaluate your system with a goal of lowering the forces and moments that act on these bends.