Re: [deal.II] [Assigning boundary value to node]

[Wolfgang Bangerth]

Veerendra:

> I'm currently working on solving an elasticity problem based on the step-8
> tutorial. In my simulation, I've successfully prescribed boundary values for
> an edge of the triangulation using the following code:
>
>  VectorTools::interpolate_boundary_values( mapping, dof_handler,
>                                               3,
>                                               Functions::ZeroFunction<dim>(dim),
>                                               constraints,
>
> ComponentMask(std::vector<bool>{true, false}));
>
> In this code, '3' represents the boundary ID of an edge. However, I now need
> to assign these same boundary values to a node instead of the entire edge.
> Could you please advise on how to implement this?

This is one of the more frequently asked questions, but I realize that we do
not document this well. I've tried to write up an answer here:
https://github.com/dealii/dealii/pull/16232/files

In short, there is no function for this in deal.II because this is not a
mathematically well-posed operation -- regardless of the fact that it is
commonly done in solid mechanics codes.

The linked patch also describes what you need to do if you really want to
impose constraints on individual vertices.

Best
W.

--
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Wolfgang Bangerth email: bang...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/