Dear Prof. Wolfgang Bangerth, > In that case, it is not enough to only pin the displacements at > one vertex of your domain. That kills the translation mode. But you still > need > to kill the rotation mode as well, which is one additional degree of > freedom > in 2d (for a total of 3) and 3 more degrees of freedom in 3d (for a total > of 6).
Your comment is very exact and helpful! I found two ways to constrain several dofs (as you mentioned, at least 3 dofs in 2D) for my problem: 1. I can use the "add_line" function, and do not use the "apply_boundary_values" function; or 2 . I can directly modify "std::map<types::global_dof_index, double> boundary_values" and use the "apply_boundary_values" function. *I wonder if the above two ways are the same in dealii's internal implemenation?* Furthermore, it is amazing to receive your reply! I have seen most of your lectures on dealii on youtube. These lectures are very very helpful! Thanks very much. Best, Pai -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
