Probleme during OSSMOOTH

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

Hello,

 

I am currently optimizing topologically a part and after the optimization I can see a hole created in my part.

But when I am doing the OSSMOOTH operation for FEA Re-Analysis, the hole is filling with small element with doesn't correspond to my optimized model (as you can see on the pictures in attachments).

Moreover if I am trying to do a FEA Re-Analysis with the 'bad-optimized' model, I will have the following message: 

 

 Element # 1273589, element type TETRA.
 
 *** PROGRAM STOPPED: ERRORS DURING ELEMENT QUALITY CHECK.

 

Could you help me with that problem ?

 

Thanks

<?xml version="1.0" encoding="UTF-8"?>Filling hole during ossmooth.PNG

Answers

  • Udhay Rohith
    Udhay Rohith Altair Community Member
    edited May 2017

    Hi Petavy,

     

    To avoid Element quality error, you can use PARAM --> CHECKEL_V1 --> No. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi Udhay,

     

    Thanks for your advice because I can now run a FEA Re-Analysis.

     

    My last problem is with the 'filling' with OSSMOOTH

  • Udhay Rohith
    Udhay Rohith Altair Community Member
    edited May 2017

    Hi Petavy,

     

    You should check the threshold value while doing OSSmooth FEA reanalysis.For viewing Element Densities you should select Result --> Plot --> Iso. You can change the Current value from 0.01(nothing removed) to 1 (completely removed material from DESPROP). By default we will use 0.15 for optimum. You can use your judgement and this value is the threshold value for OSSmooth. Depending upon the threshold value the elements will be taken for the analysis. Hope this will help you.

     

     

    <?xml version="1.0" encoding="UTF-8"?>1.PNG

    <?xml version="1.0" encoding="UTF-8"?>2.PNG

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi Udhay,

     

    I have already try with changing the threshold value and it doesn't change.

    In fact as you can see in the picture (in my first post) I can plot the Iso on my results. But when I am trying to OSSmooth with the same Iso value I don't have the contour, and that's my problem. Whatever the Isovalue is the OSSmooth doesn't recreate the correct geometry with the hole inside.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi @Petavy

     

    When using OSSmooth you will get any density contour. Did you include any manufacturing constraints like draw direction?

     

    Can you activate draw recovery in OSSmooth panel and try again?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi Prakash,

     

    I didn't include any manufacturing constraints like draw direction. I only use a Pattern Grouping with cylindric repetition with symetry.

     

    I have tried to activate draw recovery and even connection detect in OSSmooth panel and it still doesn't work ..

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi,

     

    Can you share the .fem file with us?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    Hi Prakash,

     

    I won't be able to share .fem file due to confidentiality of the part.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    @Petavy

     

    I tried on a simple model and I am able to see changes in material density as I change the Iso value in OSSMooth.

     

    Do you see any error or warning messages when you perform OSSmoothing?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2017

    There is no error or warning message when performing OSSmoothing.

     

    I am doing OSSmooth with that window and with all parameters unselected

    <?xml version="1.0" encoding="UTF-8"?>OSSmooth 1.PNG

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2017

    @Petavy

     

    This could be a model specific issue. Can you try to change the parameters as shown and provide a appropriate element size

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2017

    This should be a model specific issue ..

     

    I have try to change the parameters with an appropriate elements size but results is still the same as you can see

    <?xml version="1.0" encoding="UTF-8"?>OSSmooth 2.PNG