Dear FEniCS Community,
I have a question in my mind that has been bothering me for a while now. I could not find an answer to this question, and therefore, I am putting it here. Any help will be highly appreciated
Let’s say I have a vector-valued problem in a 3D domain. My DoFs are simply x,y, and z movements of corners or vertices of triangular elements and I am simply using 1st order Lagrange polynomial space for approximation.
My question is, lets say I have to define DirichletBC on Surface1 of my 3D domain, could I define it only for one DoF (let’s say value) without setting the other two DoFs (value,value) on this boundary to zero or not mentioning them at all? The values of the other two DoFs (value,value) at an edge of this Surface1 are already defined as a DirichletBC at an edge of Surface2. Which means, both these surfaces share a common edge. Hence, I cannot set the other two DoFs (value,value) of Surface1 to zero or some other value because I have already defined values for common nodes in the DirichletBC for Surface2. However, I do want to define the value for third DoF for Surface1 (value)
Moreover, the values of DirichletBC in my case are some interpolation functions which vary with the coordinates of my geometry, so I cannot just fix single values for these DoFs at these surfaces.
I hope you get my problem. Any help will be highly appreciated!