discrete size-optimization - error 1562

Rahul_P1
Rahul_P1
Altair Employee
edited October 2020 in Community Q&A

Hello
I permenantly get the following Error-Message while discrete size-optimization of a composite layup.

*** ERROR # 1562 ***
for element id = 30001.
Singular matrix b3 in composite homogenization precludes calculation of shear
stiffness. Make sure that composite has non-zero stiffness in all directions.
This error violates mathematical requirements and must be corrected.
This error occurs in module 'asmbdrv'.

My problem is, that I don't know where I probably made the mistake. I already compared to successful optimizations. I also don't understand, why this error occures in this step instead in a privious like free-size optimization.

best regards

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Answers

  • Rahul_P1
    Rahul_P1
    Altair Employee
    edited September 2014

    Hi Lukas,

    A quick thing to try for you could be to check if the composite layers all have thickness above 0,

    The initial value and the lower bound values of the design variable that refers the composite layers thickness need to be higher than 0 and you could maybe increase the lower bound value and try as well.

    The error is most likely due to the material definition. 

  • Rahul_P1
    Rahul_P1
    Altair Employee
    edited September 2014

    Hi
    I found the problem in the material-definition of the composite.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2015

    Hi,

     

    I get the same error and I tried all of the above but it won't work...

    The strange thing is that when I adjust the TMANUF of the plies to a value below a certain value per ply, I don't get the error. Any ideas?

     

    Kind regards,

    Sam

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2015

    Hi Sam,

     

    I am checking with experts on this.

     

    I will update to you on this as soon as possible.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2017
    Altair Forum User said:

    Hi Sam,

     

     

     

     

    I am checking with experts on this.

     

     

     

     

     

    I will update to you on this as soon as possible.

     

    Hello prakash,

     

    I'm facing the same problem, Did you maybe find a solution for this?

     

    With kind regards,

     

    Jelle

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited August 2017

    Hi Jelle,

     

    Please check the stack and ply properties and check the material data you provided. 

     

    If there is no stiffness to element, this means the element has zero thickness or material data is incorrect. 

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