Hi, > On Nov 6, 2019, at 12:27 PM, Stogner, Roy H <royst...@ices.utexas.edu> wrote: > > > On Wed, 6 Nov 2019, gmail wrote: > >> I noticed that periodic BC does not work for FEClough. I see the >> functions for it but I’m guessing it was never implemented. > > Could you be more specific? > FEGenericBase::compute_periodic_constraints is supposed to work for > every scalar-valued FE type.
I’m doing a nonlinear mixed laplacian and bilaplacian with PetscDM. My energy is something like: E=\int \left(w(\phi)+A(\nabla\phi/|\nabla\phi)^2 \xi^2 |\nabla\phi|^2 +\beta\xi^4 |\nabla^2\phi|^2 \right) dx (1) where w is a polynomial and A is a messy scalar function of vector the normal to \phi (\nabla\phi/|\nabla\phi). I’m trying to solve the nonlinear Euler-Lagrange \partial E/\partial \phi (\tilde{\phi})=0 \forall\tilde{\phi} (2) The natural boundary condition of this gives some messy flux on the boundary = 0. No when I try to solve (2) with \phi interpolated with FEClough, if I enforce periodicity it does not work and gives me exactly the same solution as though the periodic boundary is not there. When I do the same with \beta\equiv0 and solve (2) with FELagrange and periodic it works perfectly as expected. > >> My question is wether periodic BCs do work for FEHermite or is there >> a reason why the current implementation would not work for C1 >> basses. > > We combine Hermite bases with periodic BCs in miscellaneous ex7, > though I don't think we have good enough assertion coverage of the > results for me to swear there's been no regressions, especially if > you're correct and something's no longer working with the > Clough-Tocher basis. Thanks. I guess to reproduce the error, I can try to replace Hermite with Clough-Tocher and see if this gives the same output! > --- > Roy _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users