Mapped meshing: Two adjacent volumes with overlapping areas 1

[siggi84]

Hello,

I am having a problem with 3d mapped meshing. How can I mesh two adjacent volumes with mapped meshing if the adjacent areas overlap, but are not identical? If the adjacent areas are identical this is straight forward, you just mesh one of the volumes, then the other and finally use NUMMRG to merge the elements.

An example geometry would be:
/PREP7
BLOCK,-5,5,-5,5,-5,5,
!BLOCK,5,8,-5,5,-5,5, ! (Identical areas)
BLOCK,5,8,-2,2,-2,2, ! (Overlapping areas)
ET,1,SOLID69

Best regards,
Sigurdur

 

[slumdogengineer]

Unfortunately the way the ansys mesher works, it sees separate areas as separate, and thus meshes them separately unless they share common lines. So your options are either:

Redefine your geometry so that where volumes join they share common areas. In your case this would involve chopping up the volumes as bit.

Or, specify the mesh sizing so that the elements coincide with mapped meshing, then merge nodes to create a continuous mesh. Eg, in your example, size the edges of the larger face to 10 elements, and the smaller face to 4. When map-meshed, the meshes will overlap. Issue NUMMRG,NODE and the coincident nodes will merge.

 

[siggi84]

Thank you slumdogengineer,

I had already realized that I could chop the volume into pieces, sharing areas (and lines). But I didn't realize I could define the mesh sizing such that the elements coincide. By combing those two methods it seems like I can mesh my geometry.

Best regards,
siggi84