Problem with import of 2D shell and 3D hexa elements with OSSmooth

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

Hello!

We have the following problem by using OSSmooth for a FEA reanalysis:

Our component is made up of a core (blue) and a shell (red/orange). The core has Hex 8 3D-Elements with the Card Image MAT 1 and PSolid. In order to create a shell around the core of the component, we used the tool 'Find Faces'. Thus we got a shell around the core with Quad 4 2D-Elements. We used the Card Image MAT8 and PShell with an offset to the outside T=2mm. Therefore there should be no intersection between the two kinds of elements (see figure 1). Both the core and the shell was defined as design space so that we optimized them both in a successful optimization. See figure 2: Holes and notches were created in the shell as well as in the core.

Afterwards, we tried to import the optimized geometry with OSSmotth by using the following settings: FEA Reanalysis, iso surface, remesh, trias as mesh type and two layers attached. As a result the 3D-Elements has been updated according to the optimization result, but not the shell (see figure 3). Furthermore we got a very questionably visualization of the shell elements: At the attachment points between core and shell, the shell elements strangely stick to the outside and inside (see figure 4 and 5).

Are there any mistakes in our settings or in the modelling?

 

Thank you very much in advance for your tips and advices!

 

Greetings

 

Martin

 

<?xml version="1.0" encoding="UTF-8"?>figure1.jpg

<?xml version="1.0" encoding="UTF-8"?>figure2.jpg

<?xml version="1.0" encoding="UTF-8"?>figure3.png

<?xml version="1.0" encoding="UTF-8"?>figure4.png

<?xml version="1.0" encoding="UTF-8"?>figure5.png

Answers

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

    Hi Martin,

     

    What about the ISO value?

     

    Is it same as what you had in HyperView?

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

    Yes, we used the same ISO value.

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

    Is it possible for you to share the model file, h3d and .sh file to test at our end?

     

    If the same issue is reproduced here, I will check with developers on the same. 

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

    Okay, thank you!

     

     

     

     

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

    Hi Martin,

     

    What is the ISO you are using?

     

    I have used 0.1 and thickened the shells and everything looks fine. Looks like its more a visualization issue and re-meshing the tria meshed areas should fix.

     

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

    Hi Prakash!

    Thank you very much for your effort. We just analyzed the shell mass of the original model with the shell mass of the optimized model in Hypermesh after OSSmooth:

    The shell mass after OSSmooth is almost the same than before the optimization, which means that the shell was not updated after OSSmooth as it should be according to the optimization.

    Therefore it should not be only a visualization problem. Do you have a picture of your output model? Did you see the correct optimized shell in Hypermesh?

    We tried to remesh it and the message 'self-intersection' came up...

     

    Thank you for any hints

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

    Hi Martin,

     

    I need to check the mass before and optimization. I will get back to you about this soon. 

     

    Meanwhile I tried with ISO 0.3 and I see the turquoise blue component elements are on the surface of Red component and I see no intersection. 

    <?xml version="1.0" encoding="UTF-8"?>m2.PNG

    <?xml version="1.0" encoding="UTF-8"?>M1.PNG