Surface mesh and nodes association

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hi there!

Would someone please explain me one thing?

I have a complex solid model. I split it on parts. Each of parts have own plane of symmetry. So I split each one to mesh just half (quarter).

Then after surface mesh of half (quarter) I reflect 2d mesh to opposite part and associate nodes to it. After I try to mesh faces of the connected parts. But time to time mesher not 'feels' associated nodes. Often it not 'feels' associated nodes for edges with T-connections (works for only 2 surfaces of 3).

It makes me crazy...

 

Thnx in advance for answer.

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    Hi,

    For solid its recommended to check connectivity using faces option.

    Tools - Faces option.See attached screenshot.

     

    Regards

    Rahul R

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Thanks Rahul.

    All solids are connected well by Boolean operations and have 'yellow' surfaces inside. All T-connection edges are 'yellow' too.

    Trouble with mesh looks like that:

     

     

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

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    Hi,

    Whenever you use Reflect option for reflecting element then element will not be connected at that junction and for solid components it will give T connection.

    Always use these option for equivalencing node .( Free edges for 2D or Faces for 3D )

     

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    After mesh reflection I associate new nodes with solid. And it seems to be OK.

    But what's problem with original one? Look picture.

    I make reflect for 2 3d meshes. For smaller one all right but for another one mesh connection fails.

    What a difference?

     

    <?xml version="1.0" encoding="UTF-8"?>nodes_assotiation2.png

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    Mesh connectivity don't happens automatically in the case of reflect command. Such regions you can attain mesh connectivity using Automesh with remesh option for 2d elements.If possible share your model file with below ftp link.

    https://ftam1.altair.com/filedrop/rahul.rajan@altair.com

     

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    OK.

    Lets forget about reflection.

    Sometimes mesh not feels nodes associated to edge/surf.

    How can I fix it? 

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Can someone give recommendations for match meshing of T-connected surfaces?

    I wanna mesh parted solid:

    - solid parts connected by Boolean (common surf is yellow);

    - 1st part 3d meshed

    - faces extracted to the common surf

    - nodes associated to the common surf

    - when I try to mesh surf of the 2nd body mesh not feels nodes on the edge of the common surf

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Rahul, thanks a lot for your answers.

    Obviously I'm doing something wrong.

    I have sent you example model.

    I hope you'll explain what I'm doing wrong.

    Thank you again.

    <?xml version="1.0" encoding="UTF-8"?>mesh_fail2.png

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    So I have found some solution of the problem.

     

    If we want got matched meshes of two bodies if one of them with boundary layers we have to:

     

    - merge the bodies (no common surfs: no yellow surf or edges, only green one)

    - extract  faces from the 1st body

    - copy elements from meshed surf to the surf of the 2nd body

    - associate nodes of copied elements to the surf

    - mesh rest of the surfs of the 2nd body

    - use copied elements as 'fixed w/o BL' for CFD tetra.

     

    Regards.

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    Thanks for the update.

     

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2017

    Hi @Taras,

     

    I am stuck on the same kind of issue as you were. Could you explain to me some steps ? :

     - how do you merge two bodies ? I tried assemblies but it did not work out

     - how do you extract the surfaces of one body ? 

     - by copying the elements do you mean project or really copying ? 

     - how do you associate nodes to a surface ? 

     

    Thanks in advance,

    Alice

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2017

    I am most interested in the question of extracting the surfaces, if you have an answer for this.

     

    Thanks

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2019

    To the last question of Alicia,

     

    lets say you have a solid component. If you delete this solid, only its surfaces will remain. Alternatively you can go to organise entities, select the surface of the displayed body, and copy them to a new component. New component is made of surfaces now.

     

    I know this is late but might be handy for other users

    Regards