The intersection step completes the interface creation process by populating the interface boundary nodes with faces from the original boundaries. The faces belonging to the original boundary are removed. For a perfect intersection, where the matching areas of the original boundaries is the same, then the boundaries are left with zero faces. The boundary nodes however are not removed as the intersection process is reversible.
Should the intersection process not be perfect or the areas of the original boundaries are different, then there will be some faces remaining in the original boundary nodes. Depending on the situation, you should examine these left over faces. If they are acceptable then you should assign the appropriate boundary types and conditions to them. If they are not acceptable then the intersecting tolerance can be changed and the interface reset before trying the intersecting process again.
Once the interfaces have been created or reset, the intersection process can be performed by manually initializing the solution. In the case of repeating interfaces used for sliding mesh calculations, the re-intersection is done dynamically. The results of the intersection process will be displayed in the Output window along with messages related to the other initialization processes:
Additional information can be displayed in the output window by changing the interface verbosity.
On selecting the nodes of the interface boundaries within the Representations node, there will now be a non-zero value for the number of faces in the Properties window:
The interface boundary node will also now be active while the original boundary node linked with the interface will be greyed out if it has zero faces left in it as described previously.
The intersection process will usually increase the number of faces that exist at the boundaries making up the interface. This is due to the process of subdividing the boundaries on each side so that a conformal, one-to-one connection is formed between each face making up the interface. An example before and after illustration showing the interface intersections on a periodic interface is shown below:
The intersection process may also introduce additional vertices into the model. This is not permanent and is undone when either the interface is reset or deleted. Should the mesh also be exported at this point then the additional face divisions and vertices are not included. That is, the mesh is exported as if the interfaces did not exist.
