3D Hex volume mesh of brain

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

Hi,

 

I am struggling to create a hexa mesh (it must be hexa) of a brain. I have a STL file and a 2D Surface mesh. No matter what I try I cannot 'fill' the volume mesh. I can do a tetra mesh but require a hexa. I have tried Hypermesh and SimLab.

 

Thanks

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Answers

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited September 2017

    Where's the STL file? where's the 2D surface mesh?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Here is the surface mesh (in vtk format and abaqus import file) and the STL of the brain. thank you!

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited September 2017

    Further, these are my required criteria:

    Minimum Jacobian of 0.3;

    50,000 - 70,000 elements

     

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited September 2017

    Hey, you can not make a HM model?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Hi, I have attached my file.

    The 'brainVmesh' is a 3D mesh created in othersoftware which needs refining as there is clear errors. I have tried numerous methods over the past 2 weeks and have not progressed so I decided to create the volume mesh in Hypermesh. The 'brain mode'l is the STL of the brain. 

    The 'alteredSmesh' is the surface mesh, remeshed in HM. The 'smeshbase' is the base surface mesh. 

     

    I just tried using morphing to create the mesh and my results are in the file also along with the block I used to try morphing.

     

    Any help would be greatly appreciated.

     

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    I also have tried shrink wrapping from the 2D surface mesh. This gave a resulting 3D mesh with too many elements failing other criteria. 15% had length <1mm (I would like mim length = 1mm) and 15% aspect ratio > 3. 

    Unable to find an attachment - read this blog

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited September 2017

    I also have tried shrink wrapping from the 2D surface mesh. This gave a resulting 3D mesh with too many elements failing other criteria. 15% had length <1mm (I would like mim length = 1mm) and 15% aspect ratio > 3. 

    I can't found how to control these parameters yet.

     

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    SO I have remade the initial volume mesh with much better results, however I am still getting a small number of elements failing jacobian < 0.3. I have separated these elements and want to re-mesh the failed hexa into tetra elements, however I am getting unusual results when I do so. Any advice? I have attached a new file. 

    I can split the elements but i would prefer to 3D tetra remesh

    Unable to find an attachment - read this blog

  • Q.Nguyen-Dai
    Q.Nguyen-Dai Altair Community Member
    edited September 2017

    If you would like to remesh some hexa elements into tet, you have to use un layer of pyramid element to fit hexa elements.

    Are you sure your solver supports PYRAMID elements?