Modelling and Connecting Stiffeners

Hi,

I have started working heavily with Abaqus a few months ago, but still am quite a novice. After several smaller projects, I am currently trying to analyze a ship. The hull works perfectly and I am now in the process of implementing the internal structure and got a bit stuck on two questions:
1. Are Tie constraints (node-to-surface) actually the best method to connect the hull (one piece) and the bulkheads? Both are shell elements (meshed using S4R) and the model is using Inertia Relief.
2. I cannot decide whether to model the quadratic-shaped stiffeners using beam elements or shell elements. Using shell elements I could use the section thickness to make them quadratic. Beams seem easier, but how do they behave in complex shapes (i.e. 90-degree bends)? And (with regards to question 1), would I also use Tie constraints to connect beams to a shell (node-to-surface)? Finally, I have also looked into stringers to be used as the stiffeners, but they cannot be assigned a quadratic shape nor be moved properly on top of a shell (their center is in the shell). What speaks for stringers in a situation like this?

Thank you!

Julian