I would add to this that you should always try to have three elements thick minimum on members you are analyzing.This is essentially the reason that sheet metal drives you to the mid-plane method. In order to get three elements thick on sheet metal your mesh size will be so small that you will create a monster that you likely will have a hard time dealing with.
I experimented some a few years ago with larger components that were solid meshed and found that there is little difference between modeling a fillet weld and including it into your analysis vs. just gluing the elements together where they join for the analysis.
My $.02 FWIW.
Bob Henry REH Technical Consulting Canonsburg, PA 15317