On 08/19/2013 04:38 AM, Roy Stogner wrote: > > On Mon, 19 Aug 2013, David Knezevic wrote: > >> DirichletBoundary objects currently work based on boundary IDs. I'd like >> to be able to use DirichletBoundary objects to impose boundary >> conditions on boundary nodes and/or edges of a mesh. >> >> The motivation is to use Node or Edge Dirichlet boundary conditions to >> impose boundary conditions in structural analysis that don't constrain >> rotation (e.g. to provide a simple way to model joints or pins). > > Makes perfect sense. > >> I guess the target Node or Edge could be identified by passing in >> multiple boundary IDs and imposing the BC on the nodes or edges that >> belong to all of those IDs. > > We have boundary IDs that apply to nodes though, don't we? I wonder > if the right thing to do isn't just to add the same structure for > edges and then make the dirichlet constraints code take notice.
This approach would be great, I think. I haven't used boundary IDs that apply to nodes before. I guess you're referring to "nodesets" in BoundaryInfo? That looks convenient. > >> Would this be workable within the current DirichletBoundary framework >> (perhaps there are some issues since it presumably uses L2 project on >> boundaries...) > > For parallel consistency we actually do: > 1. Interpolate at nodes > 2. L2 project any edge degrees of freedom left over when holding node > dofs fixed > 3. L2 project any face dofs left over when holding node and edge dofs > fixed > > So it'd actually be relatively straightforward to mix node and edge > dirichlet conditions into that. OK, great! > >> and does this seem like a change of general interest? If so, I'm >> happy to work on it. > > I'm currently cringing because I have an unmerged branch that edits a > ton of dirichlet constraints code to handle adjoint problems with > heterogeneous Dirichlet boundaries, and I don't want a mess of merge > conflicts. > > It's passing make check, though, so I suppose I can turn it into a > pull request even though it's not feature complete. As luck would > have it, I already made all the changes that might have caused > conflicts. No rush. I'd rather wait until you merge your branch. Best, David ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Libmesh-devel mailing list Libmesh-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-devel
