NETGEN - Merge mesh
 

Dear all!

I am using netgen 5.3.1 and work on merging meshes. Tried two ways which worked out with very simple geometries but no success with more complex ones:

1.) First, I generated and saved two separate, independent surface meshes which were refined on the interface patch. Merging them by opening one and merging with the second (File > Merge Mesh ...) tells me that meshes are merged but does not show the second mesh in the GUI nor saves the second surface in the merged vol-file. Interestingly, points are joined! However, volume-meshing the merged file always leads to a crash "Segmentation fault (core dumped)".

2.) Create two independent volume meshes, load and merge like above also shows only the first surface but not the second. Furthermore, netgen tells me "121146 elements are not matching !!!" where 121146 is the number of surface elements of the second geometry. Interestingly, the vol-file of the merged geometry joins points, edges and elements, but again no surfaces. Opening the vol-file with Calculix allows to identify the different element domains but only the surface of the first geometry. I Also need the surface of the second geometry as I defined several boundary patches in netgen.

I do not need conforming meshes at the interface as Calculix allows to connect independent meshes, but I need both the elements and the surfaces of the two domains in one mesh in order to define respective element and surface sets.

I kindly ask you for advice!

Regards,
Aram

Hi!

For now I solved the problem with a (dirty) workaround: I modified the text vol-file of the merged mesh by adding the missing surface elements in the correct order. Applying the merged mesh to Calculix works so far.


Nevertheless, I hope I'm just missing something while generating the merged mesh with netgen so this workaround won't be necessary in future. Hope somebody can give me a hint how to do this properly.

Cheers,
Aram