Tria mesh and free edges

Altair Forum User

Hi all,

I have a a model composed by about 10 parts. The model was made into Catia. After importing the geometry into Hypermesh, I linked the parts in contact between boolean operations. Now the topology of the model is correct and I want to create a 3D mesh of all parts. The problem is that for some components I'm not able to create 3D mesh by tetra meshing because the elements contains free edges. I read somewhere that a way to fix this problem is to use edge panel in tools but unluckily It didn't work for me. Can someone help me suggesting the best way to procede?

I also tried to realize 2d mesh over the component surfaces and in this case there's a very strange problem. In fact automesh process works without issues or warning and I'm also able to visualize the preview of the mesh (green), but when I leave the automesh panel mesh is present only on some of the surfaces I selected (in particular, mesh is not applied to surfaces adjacent on free edges I visualized by edge panel).

 

Here's the model:

https://www.dropbox.com/s/3iaso5c0pkxqod8/2.hm?dl=0

 

The components that I'm unable to mesh are ID 2,4 and 20.

Altair Forum User

Hi,

Please try by following the steps below:
 >Check for unequivalenced nodes using Tools > Edges and equivalence them (Especially component 2 has many free edges, enclose them and try meshing)

 >Find the free edges or T connections (edges connected to three or more elements) in a group of shell elements in Tools > Edges panel.

 

 

Altair Forum User

Hi,

thanks for your reply. I have to follow these steps after or before tetrameshing? If I do it before it says me that there aren't elements to equivalence, while if I try later I need to use a very high tollerance value which twists The mesh.

Why I'm not able to create a 2D mesh over shared surfaces in element N^2?

 

Thanks!

Altair Forum User

Hi,

The model should be totally enclosed and only then tetramesh can be created. Please equivalence the free edges and try tetramesh.

I just modified the model and has sent you. Please review it.

Altair Forum User

Altair Forum User said:

Hi,

The model should be totally enclosed and only then tetramesh can be created. Please equivalence the free edges and try tetramesh.

I just modified the model and has sent you. Please review it.

 

Hi,

thanks for your support? Did you send it to me by PM? I can't found it.

 

Altair Forum User

Hi, 

I have sent to your email which is registered with us.

Altair Forum User

Hi, 

I'm sorry but I was unable to find it (I checked also in spam folder). I updated my email andress (from hotmail to Gmail). Can you resend it? Thank you!

Altair Forum User

Hi,

thanks for your precious support. I tried to reproduce steps that you described. I created a 2d mesh over component N.2 and next used equivalence tool. When I use tetrameshing I get the same error (tria mesh contains free edges). Can you describe me more specifically which steps you have followed? 

 

 

Altair Forum User

Hi,

As mentioned before, to perform a tetramesh we should have an enclosed volume. I closed (using spline or ruled command) all the free edges in the compoenet (part 2) and has done the tetramesh.

Altair Forum User

Hi George,

thanks for your support. After a deep investigation I think that problem is related to this surface. Applying color normal tool, here's the result:

 

<?xml version="1.0" encoding="UTF-8"?>

 

In fact the first error displayed during tetra meshing is 'problem with surfaces orientation...' . How can I fix it? Any ideas? Im becoming crazy, one side is correct and another side no, part is perfectly symmetrical! 

Altair Forum User

Hi,

Can you uncheck the Use curvature and Use Proximity options in Volume tetra panel and try meshing?.

Altair Forum User

Altair Forum User said:

Hi,

Can you uncheck the Use curvature and Use Proximity options in Volume tetra panel and try meshing?.

 

Hi George,

thanks! I fixed in this way.