I'm probably missing something basic, but I haven't been able to find the answer to this--

I want to tear a solid object (either a solid/watertight mesh or simply an extruded object with an output back) using vellum, with an object pushing out from inside and breaking the tear/fracture. I assume there would be a fracture (either RBD material, or voronoi, or boolean), and in the vellum setup, after the cloth and struts/pressure/tets/whatever, append a weld. The problem is that I can't get the weld to recognize the inside fractured edges as the parts that need to be attached. (I've also tried stitching points to a similar lack of avail.) Perhaps there's some sort of grouping I need to do? Any suggestions on how I can get a solid object with welded pieces so something can tear its way out?

Thanks for any help!