how to ensure matching nodes for two parts in contact

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

Hi,

 

I have two 3D parts in contact. I want to ensure matching nodes between the parts so that the contact is good in FE. How do I do that please. I am using tet elements.

 

Thanks

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Hi,

    Let say you have two circular plates lying on one another. Mesh the first plate then translate or reflect same mesh to other plate.

    Translate and Reflect would help you to get same pattern.

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Thanks Rahul.

     

    How do make sure we have matching nodes when the pasrt are not similar or have the same touching surface?

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Use (Geometry : Surface edit:trim with lines) to get desired cut in component.

    See attached thumbnail.

    <?xml version="1.0" encoding="UTF-8"?>post-36845-0-87389000-1434366279_thumb.j

    <?xml version="1.0" encoding="UTF-8"?>post-36845-0-14604500-1434366281_thumb.j

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    My parts are like this. The red one is hollow inside  (with a thickness) and the yellow one fit inside. How will the mesh share similar nodes if I mesh them seperately with the same element size?

    <?xml version="1.0" encoding="UTF-8"?>post-33908-0-21395900-1434367372_thumb.g

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Hi,

    In such cases you could use red coloured component internal faces mesh.There are many options like translate,project,scale or morphing technique would help you to get same mesh.

    If possible could you share your model.after that we can suggest exact way to get desired output.

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Here it is:

     

    https://www.dropbox.com/s/4uvf5jeuy544zvt/SHARE.hm?dl=0

     

    Thanks

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Here's my suggestion:

    1. Separate the component 'l5cort' into two components: internal & external
    2. With 'l5cort_int' & 'l5cort_ext' you can mesh the 1st volume 'm_l5cort_TET'
    3. With 'l5cort_int' you can mesh the 2nd volume 'm_l5trab_TET'
    4. Goto page '3D' => 'detach' then select 'm_i5trab_TET' to detach them from the 1st

    Now you got two volume mesh with coincident nodes at contact surface.

    See my screenshot.

     

    HTH,

     

    Update: here's your HM model modified.

    <?xml version="1.0" encoding="UTF-8"?>post-889-0-04228400-1434427660_thumb.png

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Hi,

     

    I hope above suggestion would have worked fine.

     

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    thanks!

    Did you create the l5cort from both internal and external?

    I am gettting bad elements when I try this

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Even with the internal mesh I get problems when I try to convert the 2D surface mesh to a volumetric mesh. It says mesh not enclosed.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    @dilen: from your HM model, I make directly 3D TET mesh from your surface mesh without any modification. It should work.

    If you have bad quality element, it's another history image/emoticons/default_smile.png' alt=':)' srcset='/emoticons/smile@2x.png 2x' width='20' height='20'>

    You can also refine your surface mesh.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Did you do surface mesh (F12) and then tetramesh. I am doing that with different mesh size and it's not working.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Do you use Hypermesh 13 with all updates ?

    My version is 13.0.112_hotfix.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    I have managed to do it using the same method earlier but this time it worked. Don't know why.

    One last thing, how would you ensure matching node between these entitoes, please?

     

     

     

     

    <?xml version="1.0" encoding="UTF-8"?>post-33908-0-00467400-1434636887_thumb.g

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Anyone has a method please?

    Thanks

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Hi,

    Split surfaces where both the faces are mating. Then mesh one face and duplicate it to new component then using detach command you vcan ensure node matching.

    Regards

    Rahul R

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Also check with Mesh edit: Imprint option.

    Attached thumbnail for reference.

    Regards

    Rahul R

    <?xml version="1.0" encoding="UTF-8"?>post-36845-0-23728300-1435054162_thumb.j

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    I tried the imprint options but the nodes on each part are not matching.

    I'm not sure how to go about splitting surfaces using one part as the cutting tool. Any advcie please?

     

    Thanks

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2015

    Use geomtry page:surface edit option:trim with surfaces n select last column self intersecting surfaces.

    Regards

    Rahul R

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    Hi Dai,

     

    I have a similar question about the connectivity issue of the tetrahedral element of two bodies. I am trying to mesh an assembly, in which, one body penetrates into another body. I want to mesh them using 3D tetrahedral element. I first mesh the outer body and then mesh the other body which penetrates the first body. I chose the option 'match existing mesh'. However, the nodes of elements of thees two bodies do not connect with each other. I read your post and download the .hm file you created. But I can't figure out how did you separate the one component into two components and what is the purpose of this. Below is the link of my .hm file. Could you please show me detailed step for meshing my model? 

     

    https://www.dropbox.com/s/gqd9sx4wq5nfnpl/mesh2.hm?dl=0

     

    Thank you very much

     

    Youyi

     

     

    Altair Forum User said:


    Here's my suggestion:

    1. Separate the component 'l5cort' into two components: internal & external
    2. With 'l5cort_int' & 'l5cort_ext' you can mesh the 1st volume 'm_l5cort_TET'
    3. With 'l5cort_int' you can mesh the 2nd volume 'm_l5trab_TET'
    4. Goto page '3D' => 'detach' then select 'm_i5trab_TET' to detach them from the 1st

    Now you got two volume mesh with coincident nodes at contact surface.

    See my screenshot.

     

    HTH,

     

    Update: here's your HM model modified.


  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015
    Altair Forum User said:

    Hi Dai,

     

    I have a similar question about the connectivity issue of the tetrahedral element of two bodies. I am trying to mesh an assembly, in which, one body penetrates into another body. I want to mesh them using 3D tetrahedral element. I first mesh the outer body and then mesh the other body which penetrates the first body. I chose the option 'match existing mesh'. However, the nodes of elements of thees two bodies do not connect with each other. I read your post and download the .hm file you created. But I can't figure out how did you separate the one component into two components and what is the purpose of this. Below is the link of my .hm file. Could you please show me detailed step for meshing my model? 

     

    https://www.dropbox.com/s/gqd9sx4wq5nfnpl/mesh2.hm?dl=0

     

    Thank you very much

     

    Youyi

    Hi Youyi,

    Here's my test for your mesh (see HM model & screenshot).

    Firstly, you have to work for 'skin' meshes.

    I use 'Skin_1' & 'Skin_2' to make solid mesh 'm_ReadandWriteElement_NiCoFe'

    Then, I used 'Skin_1' & 'Skin_3' to make solid mesh 'm_Coil1_Cu_double'. You can delate all Skin mesh if you not need.

     

    If you want to have two separated meshes, use '3D' => 'detach' with offset=0 to detach the second from the first one.

     

    HTH,

    <?xml version="1.0" encoding="UTF-8"?>post-889-0-91847500-1435504757_thumb.png

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited September 2015

    I still have not managed to do it. Any help please to get matching nodes.

     

    https://www.dropbox.com/s/7bkcb55tumokwyo/redprismesent.hm?dl=0

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited September 2015
    Altair Forum User said:

    I still have not managed to do it. Any help please to get matching nodes.

     

    https://www.dropbox.com/s/7bkcb55tumokwyo/redprismesent.hm?dl=0

    The working principle has explained. For your case, you need some work with Geometry before meshing.

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