Cant obtain feasible result from topology optimisation

George Gow
George Gow Altair Community Member
edited April 2022 in Community Q&A

Hi,

 

I am trying to use topology optimisation to reduce the displacement caused by two load cases applied simultaneously and reduce or maintain the mass of the model. I have set the mass as the objective and have constrained the displacements to be slightly smaller but I am not getting a feasible design. I have attached the model could someone tell me where I'm going wrong?

Many thanks,

George 

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Best Answer

  • PaulAltair
    PaulAltair
    Altair Employee
    edited April 2022 Answer ✓

    the material can't meet the constraints even with all the material (if you run analysis only they are around 7.9mm and 1.9mm), you can't reduce the material and meet them, if you reduce your constraints, e.g. to 7.5 and -1.75 or you increase your gauges then you will be able to meet the constraints.

Answers

  • Ben Buchanan
    Ben Buchanan
    Altair Employee
    edited April 2022

    If you run analysis only on your model you can see that it doesn't meet your constraint.  Since topology optimization just changes the density of the elements it will not be able to meet the criteria because it cannot add material.  If you change your base thickness to 7.5 mm and increase the DESMAX to say 80 then you will get a converged result that meets all criteria.

  • PaulAltair
    PaulAltair
    Altair Employee
    edited April 2022 Answer ✓

    the material can't meet the constraints even with all the material (if you run analysis only they are around 7.9mm and 1.9mm), you can't reduce the material and meet them, if you reduce your constraints, e.g. to 7.5 and -1.75 or you increase your gauges then you will be able to meet the constraints.

  • George Gow
    George Gow Altair Community Member
    edited April 2022
    Ben Buchanan said:

    If you run analysis only on your model you can see that it doesn't meet your constraint.  Since topology optimization just changes the density of the elements it will not be able to meet the criteria because it cannot add material.  If you change your base thickness to 7.5 mm and increase the DESMAX to say 80 then you will get a converged result that meets all criteria.

    Ah ok, that makes sense. 

     

    Thank you very much for taking the time to help me.

  • George Gow
    George Gow Altair Community Member
    edited April 2022
    Paul Sharp_21301 said:

    the material can't meet the constraints even with all the material (if you run analysis only they are around 7.9mm and 1.9mm), you can't reduce the material and meet them, if you reduce your constraints, e.g. to 7.5 and -1.75 or you increase your gauges then you will be able to meet the constraints.

    Ah ok yeah that makes sense. 

     

    Cheers for taking the time to help :)

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