Connectivity between two different 3D meshes

Altair Forum User

Dear all,

 

I am in need of some help and advice regarding to the connectivity of my two complicated parts. I created these 3D parts from CT scan and these two parts should connect with each other. However, after I did some element optimization and cleanup, the shape of the parts changed a little. I solved the intersection problem by going to Tool > penetration > > automatic recursive Intersection fix.

 

But I have no idea whether these two parts are connecting with each other or not? How can I know are there any gaps in between them? If there are, how can I solve them?

 

Any help and advice will be greatly appreciated. Thanks in advance.

 

Best,

Mushi

Altair Forum User

Try this simple method:

• Show only two mesh parts
  
• Tool -> faces -> Select two parts -> find faces
  
• Hide two parts, keep only faces
  
• Tool -> edges -> Select all faces -> find edges
  

If you got a closed volume, your two 3D mesh parts are perfectly connected. If not, you can identify easily the gaps.

Altair Forum User

Dear Mr. Dai,

 

Thanks a lot for your suggestions. But seeing as my parts are only surface meshes, I cannot find any faces through the method you mentioned above. I read through the Hypermesh tutorial and this is what I did. Please correct me if I did something wrong.

 

1) Import both surface meshes inside of Hypermesh. Create solid tetramesh for those two parts.

2) Hide those two surface mesh parts, and select the only remaining solid part (only one part).

3) Go to tools > faces > find faces. (There is only one face for the two-combined-model)

4) Tool > edges > select all elements > find edges

 

Is this the correct way to find faces and later on find the edges between the two parts?

 

Best,

Mushi

Altair Forum User

If you have Surface (2D) elements, then no need to create 3D elements and no need to extract the faces.

 

Just skip step 1,2 & 3

 

Start with step 4 Directly

 

After that

 

Goto> tools>edges>Select all elements >select preview equivalence> will show the nodes in given tolerance range. (Here you have to assume (roughly) a distance to search, and enter in the tolerance box before selecting preview equivalence ). This will show you all the nodes in that tolerance range.

 

Review the nodes shown and if you want to merge them just select Equivalence, will merge those nodes.

 

Note: Blindly don't go for Equivalence option, review all the nodes before merging. If not change the tolerance value and search again.

Altair Forum User

Dear raviteja,

 

Thank you for your reply. Initially I put tolerance as 0.0 and found no preview equivalence nodes. After noticing some of the areas are not so well-connected, I changed the tolerance value and found the result to be better. But my model is quite complicated and it is hard to check visually whether it is well-connected throughout the model or not. Is there any way for me to check after I did the equivalence step? Thanks again for your help!!! Really appreciate it.

Altair Forum User

Dear all, Happy New year!!! Hope this new year will be a good year to all. I wanted to ask for some guidance regarding on the connectivity problem again. Imagine I have two steel rod with complicated surface (spiral). Steel rod B must fit inside of steel rod A. I tried the equivalence method to connect both parts together but when I did that, I faced penetration and T-connection problem. Can anybody teach me how can I solve this? I am really in need of help now. Been trying for months but still cannot solve this problem. /emoticons/default_sad.png' alt=':(' srcset='/emoticons/sad@2x.png 2x' width='20' height='20'> Thanks in advance.

 

Best,

Mushi