Hi Jude,
> I'm have a test set up where a 3D rectangular box of randomly-packed spheres is being expanded and compressed by infinite walls anchored on either end.
If you want to simulate something like representative volume element without boundary influence, consider using periodic boundary conditions.
> The problem I'm having is that I want to be able to confine the other sides of the box, but Woo seems to be having an issue with having intersecting infinite walls which causes the simulation not ot move at all. I also have tried replacing the walls with facets but with similar results. Any help would be greatly appreciated!
Please disclose some more details about your simulation -- the best would be to post your simulation script, or explain in words what exactly are the boundary conditions (if you prescribed force, displacement and how), maybe a sketch. What does it mean that the simulation does not move? Do you get some error message? Or just no movement? There is no issue with walls intersecting each other, that scenario is in fact used rather often. Don't underestimate the code ;)
Cheers, Vaclav