Equivalencing 1D element nodes

Burner2k
Burner2k Altair Community Member
edited October 2020 in Community Q&A

Hello,

I am familiar with the procedure of merging nodes in Hypermesh but my question is regarding 1D element node merging. I created a bunch of spring elements using 1D tool bar between 2 nodes. When I check for equivalence using Tool->Edges, Hypermesh does not show any duplicate nodes at those locations. However, when I import the same mesh in to MSC Patran, Patran shows me the presence of duplicate nodes and merges them successfully.

 

Just wanted to add a little bit more info about the model. I have created a 1D element between two surfaces containing quad elements.

 

I even tried increasing the tolerance value in Hypermesh but still HM refuses to show me presence of duplicate nodes at the ends of 1D elements. I would appreciate pointers on how to resolve this in HM.

 

Thx

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Answers

  • tinh
    tinh Altair Community Member
    edited June 2017

    Hi

    Please attach a sample file

    Or post a screen shot

  • Burner2k
    Burner2k Altair Community Member
    edited June 2017

    Hi,

    I cannot share the file that I am currently working on however I can share the screenshots.

     

    Screenshot shows checking edges tool preview equiv result. On the lower left side of the screen, I think it says '0 nodes were found'.

     

    The second screenshot shows the same dat file imported in to Femap with NX Nastran showing locations where nodes merging will be performed. The locations are where CBUSH elements are present.

     

    Lastly, the third screenshot shows an existing CBUSH element in HM along with method on how it was created.

     

    Thx for the reply. Hoping to get some answers. If possible, I will try to share the dat file of a simple model with CBUSH elements created with HW 2017 later.

     

     

    <?xml version="1.0" encoding="UTF-8"?>01.PNG

    <?xml version="1.0" encoding="UTF-8"?>02.PNG

    <?xml version="1.0" encoding="UTF-8"?>03.PNG

  • tinh
    tinh Altair Community Member
    edited June 2017

    I understood.

    So you want to make zero length cbush, dont you?

    It cannot be carried out by equivalence panel, because equivalence means replacing nodes that destroyed cbush

    A simple script can make concident-node cbush

  • Burner2k
    Burner2k Altair Community Member
    edited June 2017

    Tinh,

    Nope. I don't want to make a zero length CBUSH. In fact, my CBUSH elements have finite non-zero length. My issue is why is element check function not able to equivalence CBUSH nodes like Patran/Femap can!

     

    May be HW doesn't create separate nodes while creating a CBUSH element but some how Patran/Femap is creating these nodes (at the ends of CBUSH elements) during import and thus detects presence of duplicate nodes and thus is able to merge?

  • tinh
    tinh Altair Community Member
    edited June 2017

    No, it does not separate node of cbush and quad elem. So you dont need to equivalence them. You can confirm this by panel f10>1d>free nodes => will highlight cbush nodes not equivalenced

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