Re: Terms on a physical line in 3D

[Jean-François Barthélémy]

Dear Konstantinos,

Thank you very much for your reply.

Indeed this solution works perfectly and has the advantage to handle two possibly non conformal meshes.

By the way Yves Renard has just also committed in the python interface the possibility to import a gmsh mesh including elements of dimension N-2 (option ''gmsh_with_lower_dim_elt") which somehow allows to have regions of edges on which the assembly procedures work.

Thank you again.

Best regards

Jean-François

Le lun. 16 nov. 2020 à 08:16, Konstantinos Poulios <logari81@googlemail.com> a écrit :

Dear Jean-François,

The simplest way of coupling a 1D to a 3D domain is by means of the "Interpolate" function in the general weak form assembly language in GetFEM. You can add an identity interpolation between the 1D mesh, representing your lines, and the 3D mesh representing your volume, with

add_interpolate_transformation_from_expression("3Dto1D", mesh3D, mesh1D, "X")

then, in order to couple the two domains, you can use the interpolate name "3Dto1D", or whatever you call it, in any assembly _expression_ integrated on your 1D domain, .

Best regards

Kostas

On Tue, Nov 10, 2020 at 4:29 PM Jean-François Barthélémy <jfrancois.barthelemy@gmail.com> wrote:

Dear Getfem users,

I have a 3D mesh in which physical lines are identified (ie set of edges). These lines may be on the boundary or in the interior of the domain.

I would like to build a model incorporating (linear and even nonlinear) terms on these lines (ie integration domain of dimension m.dim()-2). This could be used for example to model a concentrated line of current injection in an electric ohmic problem (rhs term) or a lineic domain of high conductivity (contributing then to the matrix term). Is there any way to do so in Getfem?

Thank you in advance

Best regards

Jean-François Barthélémy