On 4/27/10 10:20 PM, Roy Stogner wrote: > > On Tue, 27 Apr 2010, Boyce Griffith wrote: > >> I am trying to use the DofMap to impose Dirichlet-type boundary >> conditions within an explicit nonlinear mechanics solver which is >> embedded in a larger fluid-structure interaction solver. I constrain >> the velocity and force DOFs at Dirichlet boundaries to be zero by adding >> a DofConstraintRow for each of the constrained DOFs. > > This should be a good method for homogeneous constraints on LAGRANGE > (or HIERARCHIC, or pretty much anything but CLOUGH) elements. I don't > know if anyone's ever actually tested using it before, though.
I don't expect to be using anything other than LAGRANGE for a while... After adding DofConstraintRow's to the dof map, what generally needs to be (re-)initialized? Is it a good idea to call EquationSystems::reinit()? >> This seems to work well as long as I do not also have subdomains in my >> mesh; however, as soon as I start labeling different subdomains, the dof >> constraints no longer impose the boundary conditions. Is this expected >> behavior? Is there something special that I should be doing in the case >> of multiple subdomains? > > This is very surprising - unless you're adding subdomain-specific > variables, in general the only part of the code that cares about > subdomains is the I/O (to read them in and write them out), the > refinement (to assign them to new child elements), and your own user > code! Could you verify this problem in a small example? I was certainly surprised... I'll try to verify that this is the only difference between the working and non-working cases and see if I can put together a simple example. Thanks, -- Boyce ------------------------------------------------------------------------------ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
