3D Meshing Quality Check problems

Fady Farouk
Fady Farouk Altair Community Member
edited October 2020 in Community Q&A

Hello guys, i have been trying to mesh several objects for the past few days.

 

 Everytime, it all goes correctly, even the meshing, loads, responses, and when i assign the properties it says 'elements assigned'.

 

 Now when i run the topology, it says job terminated at 'Element Quality Check - element xxxx invalid element type'.

 

 It does this almost everytime - no matter the component.

 

 I try remeshing, and activated the 'REMESH' from 'opticontrol', i auto clean the geometry before meshing - same outcome.

 

 When i try to clean mesh elements it says 'unable to create hmshell.

 

Is there anyway i can bypass the element QI check?

 

I always use Volume Tetramesh - PSOLID

 

i can't fix all the broken elements manually.

 

Please advise as this has been really delaying.

 

Note: i have student edition so i cannot have more than 10,000 elements.

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Fady Farouk,

     

    Can you make sure that you have only solid elements and no shell elements in your model?

  • Fady Farouk
    Fady Farouk Altair Community Member
    edited February 2016

    I made sure i only have solid elements. Now it gives me that elements have negative jacobian... is there any way to bypass the quality check?

     

     If not can you tell me tips on making sure the automesher makes all elements that pass quality check?

     

     it gives me no errors when i assign the properties and when i make the mesh... only when i move to the final optimisation for results. It is very frustrating.

  • Fady Farouk
    Fady Farouk Altair Community Member
    edited February 2016

    Is there no trick for meshing that can stop this from happening? This isnt specific for this geometry.. i get the same error i explained earlier alot for different geometries too.

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  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi,

     

    I think the error message has nothing to the property.

     

    One particular element is failing which is a modelling error. You can either remesh that particular element or bypass element check.

     

    to bypass element check, Activate Analaysis>> control cards>> PARAM>>ELCHECK>> NO

  • Fady Farouk
    Fady Farouk Altair Community Member
    edited March 2016

    Thanks!! This helps.

     

    now moving on to another problem. I get this.

     

    Messages for the job:

     
     *** ERROR # 2148 ***
     Invalid design problem.
     All the sensitivities of response 2 (objective) are zero.
     

    my response 2 (objective) is weighted compliance.

     

     I have 3 loads in 3 load steps that i assign to the weighted compliance. I click all and press create when doing so, but when i click on the yellow 'loadsteps' button again they all seem to be unticked... i am worried this may be the problem. Is there a way to check they are correctly assigned?

     

     If not, what may be the problem? When i run the check i get no errors.

     

     Many thanks!

     

     Fady.

     

     

     

     

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  • Fady Farouk
    Fady Farouk Altair Community Member
    edited March 2016

     

     

     

     

     

     

     

     

     

     

    I should also add that i have made sure all my element properties are PSOLID.

     

     

     

     

    Thanks again.

     

    Fady

     

     

     

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  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited March 2016

    Hi,

    Could you share us .fem & .out file for debugging?

     

    Regards

    Rahul R

  • Fady Farouk
    Fady Farouk Altair Community Member
    edited November 2020

    Sure - when i run the optimisation, several files are saved. I believe they are all attached.

     

     

     

    Thanks!

    Unable to find an attachment - read this blog

  • Fady Farouk
    Fady Farouk Altair Community Member
    edited November 2020
  • Fady Farouk
    Fady Farouk Altair Community Member
    edited March 2016

    IMPORTANT UPDATE: PROBLEM SOLVED

     

     

     

    The issue was that i had applied a full constraint (SPC) to a face on a solid that i had applied the all the loads and thus loadsteps onto - and made non-designable.

     

    i.e. the load fluxes did not propagate to the designable section - because i applied full constraints (SPC) to a face on the non-designable load-bearing solid section.

     

     

     

    Many thanks anyway!

     

     Fady

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited March 2016

    Thanks for the update.

     

    Regards

    Rahul R