Hello Daniel, I think i've found where the problem was. It's because I used set_boundary_id with active_cell_iterator after global_refinement. But I found in source codes of collect_periodic_faces function it's just cell_iterator that has been used. I've instead called set_boundary_id at first then global_refinement and it goes well.
Thank you anyway. Chuyi 在 2017年6月1日星期四 UTC+2下午2:31:58，Daniel Arndt写道： > > Chuyi, > > >> i was trying to use Dealii to solve a 3-dimensional elastic-plastic >> question on a cubic by applying periodic boundary condition like in step-45 >> (v. 8.5.0). >> std::vector<GridTools::PeriodicFacePair<typename DoFHandler<dim>:: >> cell_iterator> > periodicity_vector; >> GridTools::collect_periodic_faces(dof_handler, 1, 2, 2, >> periodicity_vector);//1,2,2: the first two numbers refer to the cell >> faces at the boundary, the third number to the direction >> DoFTools::make_periodicity_constraints<DoFHandler<dim> >( >> periodicity_vector,constraint_matrix); >> >> But i got different results as i have created the mesh using >> GridGenerator::subdivided_hyper_rectangle (triangulation, rep, p1, p2);//rep >> is the repetition >> method 1 to get the mesh: >> p1 (0, 0, 0) >> p2(1, 1, 1) >> rep=(8, 8, 8) >> no global refinement >> >> method 2 to get the mesh: >> p1 (0, 0, 0) >> p2(1, 1, 1) >> rep=(1, 1, 1) >> global refinement = 3 >> >> I just wonder why there come two different results when these two meshes >> are actually the same. >> > How do the two solutions actually differ? How many constraints a created > in either of these cases? > Can you provide us with a minimal example just setting up the periodic > constraints in case they are different? > > Best, > Daniel > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
