On Fri, 5 Jan 2018, Renato Poli wrote:
I need to tie three dofs together. (u1 + C u2 + D u3=0). I read about the constraint matrix in the list, but I did not find an example to follow. The penalty method seems also a nice alternative. Is there any example of either to suggest?
In systems_of_equations_ex2.C there's an example of using a penalty term to pin pressure at one point; that's probably the closest analogy we have to what you want to do. Using DofMap::add_constraint_row() would be better (you'd be solving the correct equations!) but I don't think we have any use of it in our example codes, and it's slightly trickier: you need to ensure that the DoF you constrain isn't already constrained by e.g. hanging node constraints or boundary condition constraints. --- Roy ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
