Initial number of plies for composite optimization

moeen
moeen Altair Community Member
edited October 2020 in Community Q&A

Hi

For composite free size optimization, does it matter what thickness we use for initial ply definition, i.e. when we first define the ply in hypermesh, does it matter what thickness we put there? or we should have to use the actual ply thickness we want to manufacture. I am not talking about manufacturing constraints.

Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2019

    For analysis and optimization of composites base run needs actual ply thickness. Are you facing any problem wrt to the actual ply thickness? If so, then please make sure to have element normal aligned in one direction and material orientation.You can refer below video for same.

    https://altairuniversity.com/learning-library/preprocessing-for-composite-analysis-using-hypermesh/

  • moeen
    moeen Altair Community Member
    edited February 2019

    I am running a composite optimization analysis with a buckling constraint factor >2 and the objective is to minimize mass but the simulations is not converging

     

    Any idea what to look at? Also when i see the output file, i can see that optimization is running for 15 buckling modes but i only need to run it for 2 modes. how to set that limit ?

     

    thanks

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2019

    Can you share the .out file of run?

  • moeen
    moeen Altair Community Member
    edited February 2019

    here it is

     

    I have to terminate this analysis since the solution is not converging more then 200% constraint violation

    Unable to find an attachment - read this blog

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2019

    For the buckling constraint to be effectively maintained, an additional parameter needs to be defined.

    Click the opti control panel.

    Select MAXBUCK=.

    By default, the box preceding GBUCK= is checked automatically.

    Click return.

    Together, these two options ensure that up to 2 modes are considered in the buckling constraint.

  • moeen
    moeen Altair Community Member
    edited February 2019

    For the buckling constraint to be effectively maintained, an additional parameter needs to be defined.

    Click the opti control panel.

    Select MAXBUCK=.

    By default, the box preceding GBUCK= is checked automatically.

    Click return.

    Together, these two options ensure that up to 2 modes are considered in the buckling constraint.

     

    I have not selected MAXBUCK=2 and  GBUCK=1, but still in the output files there are 15 buckling modes. Why is this so?

    In EIGRL card i have selected ND = 2, Do I also need to define V1 and V2 in the EIGRL card? I don't know from where the software picks 15 buckling modes?

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2019

    For this case, the multiple bucking modes are automatically considered in optimization. Under the default screening setting (auto-screening), max_buck is reset to 15.

    If the auto-screening is turned off (DSCREEN,AUTO,OFF or any user defined DSCREEN in the deck), the user defined max_buck is respected.

  • moeen
    moeen Altair Community Member
    edited February 2019

    For this case, the multiple bucking modes are automatically considered in optimization. Under the default screening setting (auto-screening), max_buck is reset to 15.

    If the auto-screening is turned off (DSCREEN,AUTO,OFF or any user defined DSCREEN in the deck), the user defined max_buck is respected.

    Sorry i didn't understand.

    I have already defined that I only need 2 buckling modes then why 15 modes are selected?

    Where to find those auto screening options?

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2019

    Analysis Page:Optimization:constr screen

    Activate autoscreen and set it to off.Please refer attached pdf for DSCREEN.

    Unable to find an attachment - read this blog

  • moeen
    moeen Altair Community Member
    edited February 2019

    Analysis Page:Optimization:constr screen

    Activate autoscreen and set it to off.

     

     

    Thanks i have applied those constraints. But will this also solve the problem of convergence now?