Definition of BC on curved surface

Hello everyone,

I want to define pressure at a surface which is not straight. It is a curved shape and it is not possible to create a sub boundary by using coordinates. Is there a way to selects nodes on such a curved surface ? Is it possible to create a node-set at that surface in Abaqus as .inp file and transfer it to fenics ?

See for instance this post Extracting mesh regions for gmsh mesh .
Or this turtorial here (might be slightly out of date)

Hello dokken,

I do not use gmsh, I directly create the mesh in Abaqus as .inp and convert it to xml in Fenics. Is there a way to transfer abaqus node-sets to fenics with a predefined boundary name ?

By the way the second tutorial link that you provide contains subdomains by using coordinates with a tolerance. In my geometry there is no way to select the nodes on the surface by an equation, so it does not work for me.

You should use meshio to convert the data to xdmf.
Usage of meshio with inp is illustrated here:

Then you can load your meshes as described in the link from the previous post.

Hello dokken,

Thank you for your reply. Actually I know how to use abaqus mesh but i m seeking for how to use node-set predefined in abaqus rather than selecting in python with coordinates. The script that you provided does not help me to load the node group that was defined in abaqus. Is there any way ?

I can imagine that this could be attached to the mesh, and converted to a MeshFunction in FEniCS using meshio. Not sure how the exact conversion would be. I would Ask the developers of meshio, as They have more experience with abaqus then I have