Just had a look at Simulation 2010 SP2. Tried to create edge welds on curved surfaces. This is what I noticed and what happened.
1. Shell meshing with global bonded contact defined and compatible mesh selected for the global bond and using curvature mesh still results in an incompatible mesh.
2. In order to get a compatible mesh with shells you still have to split surfaces.
3. The automatic selection of contact sets apparently doesn't work for shells.
4. With the global contact set to bonded some shells do not bond and still fall off when the study is run.
5. Unable to save a data set of values for the edge weld. See attached Excel files.
6. Unable to define an edge weld plot showing a graph of computed values.
7. While splitting a face the computer crashed.
8. When I created a shell using an on surface sketch and the surface extrusion feature it was not possible to create an edge weld. An error message occured that said - Invalid edge selection for weld. Select a different intersecting edge on Face Set1. The same message occurs regardless of the surfaces selected. Extruding a surface from a plane to the matching surface face enable the edge weld to be created.
This was all discovered and encountered in the space of about an hour.
Interested to hear other user experiences.