Another question: I have two coaxial cylinders, one is exterior, one is interior. They share though one cylindrical face. I want to model glued surfaces. How can I make the two meshes to be compatible (nodes correspond on the touching faces). I am using Chexa20 elements.
You can do this by creating a Mesh Mating Condition between the two cylindrical faces. To create coincident node (and element faces) you will want to set the mesh mating conditions type to be Free Coincident. Mesh mating lets you create merged and compatible meshes at coincident faces.
Thank you Mark,
It works with tetrahedral elements. Thank you. I have to define the mesh-mating condition, then mesh both solids with the same element size. Is it correct? Is it possible to have different meshes on the two solids, and have this dimension modified only in the vicinity of the common face/edge? For example to first define a Mesh condion on the two faces, specifying a common value, then aply a Mating mesh and mesh the two solids? But in this case (I am thinking while I am writing) I have to mesh both solids in the same time and specify only one element size!!
My problem is that I would rather use Chexa elements (see the attached image). Here I do not know how to mesh more than one solid at a time in order to keep the mating conditions!
You don't have to create both meshes at the same time, and they can have different mesh sizes. If you mesh them separately, then the common face(s) will have a mesh size based upon the first mesh. The second mesh will use exactly the mesh on the mated faces, then transition to the desired size for the second mesh.
For CHEXA, mesh mating is used extensively. Anytime that you have to split a solid into multiple solids to produce sweepable solids, mesh mating is used to maintain consistency in the meshes at the shared faces. Mesh mating works in the same manner regardless of the solid mesh type.
Mesh mating also supports generation of pyramid elements to transition between hexa and tetra meshes. That requires generation of the hexa meshes first, followed by the tetra meshes. The tetra mesh dialog will provide an option to transition from the hexa mesh via pyramids.
I tried again to aply a mating mesh and mesh using chexa. I am creating chexa using the 3D swept mesh.
I considered a simple model, two boxes, with a common face.
I meshed first the small box, using the large faces (one of them is touching a face of the big box).
Then I meshed the big box, either using the large faces (one touching the small box), either two small faces (named 1 and 2 in the files one.jpg and two.jpg).
In both cases the meshing of the big box failed. See the two images attached to see what messages I got.
The big box has 2 source faces, but you selected only 1. Display the big box by itself and you will see. You need to sweep 2 source faces into the single target face.