Non Linear Optimization with Pretension

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

Hello All,

 

I am running a Non Linear Optimization with the following load conditions:

 

STEP-1

Assembly fit using PCONT clearance

Pretension

STEP-2

Temperature change from 23 degres to -40 degrees

 

Non linear optistruct run was clear but when I run the model for optimization I get the following error:

 

  *** ERROR # 415 ***
  Static Subcase 2 has 'STATSUB(PRETENS)' defined.
  Optimization with compliance cannot be performed.

 

Any suggestions will be highly appreciated.

 

Thanks 

Praveen

 

Answers

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

    What type of optimization you are running , Responses & Version of Hyperworks?

    Attached screenshot for Thermal compliance(Version 14.0)

    <?xml version="1.0" encoding="UTF-8"?>TCOMP.JPG

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2017

    Hi Rahul,

    My Hyperworks version is V14.0 student edition, but I can not find the 'thermal compliance' in the 'response' panel, I can only find  'temperature' response. 

    Could you advise? thanks. 

     

    Neo

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2017

    Hi @wumindao

     

    Thermal Compliance is currently not available through Student Edition. It was added in of the 14.0 updates which is not a part of Student Edition.

     

    as a workaround, you can add thermal compliance as shown in image below by editing the deck in any text pad.

     

    Thermal compliance will be a part of responses in Student Edition in coming release.

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    Hi @wumindao

     

    Thermal Compliance is currently not available through Student Edition. It was added in of the 14.0 updates which is not a part of Student Edition.

     

    as a workaround, you can add thermal compliance as shown in image below by editing the deck in any text pad.

     

    Thermal compliance will be a part of responses in Student Edition in coming release.

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

     
     
     
     
     

    Hi Prakash Pagadala,

     

    Thanks for your reply!

    I have done so, but there was an error after the run. 

    The error message is ' DRESP1 1 is not referenced from within a linear heat transfer SUBCASE.
     This type of response must be specified from within a linear heat transfer  SUBCASE.'

    (Note: DRESP1 is Thermal Compliance, I set VolumeFrac<=0.3 as a constraint, and set TCOMP be min. as objective. )

     

    Could you please advise that how to make the response 'Thermal compliance' be specified from a Subcase? 

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    Hi,

     

    Is it possible to share the model file?

     

    If yes, please use the file transfer link in my signature below to share files. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Hi,

     

    Is it possible to share the model file?

     

    If yes, please use the file transfer link in my signature below to share files. 

     
     

    Hi Prakash,

     

    I am sorry but I can't find your signature as well as the 'transfer link', the signature not displayed.

    Please find the file as attached.

     

    Actually, I want to do a thermal topology optimization , same as the one in this paper:

    https://www.researchgate.net/publication/304703093_Thermal_Topology_Optimization_in_OptiStruct_Software

    Could you suggest some examples for me to do the thermal topology optimization? Thanks very much!

     

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    @wumindao

     

    I will share another modified file with you soon by mail.

     

    But Currently QBDY1 is not allowed in design domain. You will end-up with new error message. Make neccesary modifications and run the model. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    @wumindao

     

    I will share another modified file with you soon by mail.

     

    But Currently QBDY1 is not allowed in design domain. You will end-up with new error message. Make neccesary modifications and run the model. 

     
     

    Hi Prakash,

     

    Thanks for your help! 

    Appreciate that if you could just make a simple file and shared with me.

    As refer to attached files, could you just make a file that same as chapter 6.1 in the attached paper? I have made one but the error still come out which is ' DRESP1 1 is not referenced from within a linear heat transfer SUBCASE.  This type of response must be specified from within a linear heat transfer  SUBCASE.'

    <?xml version="1.0" encoding="UTF-8"?>flat plate.png

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2020

    Hi,

     

    Try this atatched file

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

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    Hi Prakash,

     

    Your file works very well ! Thanks.

    But I modified my file (e.g., make a new component which is non-design space, added VolumeFrac) and make it looks same as your one, but the error message still come out which is ' DRESP1 1 is not referenced from within a linear heat transfer SUBCASE.  This type of response must be specified from within a linear heat transfer  SUBCASE.' .

     

    May I know where you have modified ?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    @wumindao

     

    The reason is that TCOMP response should be within subcase. I moved the response within subcase (you can edit the file and see the changes)

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited April 2017

    Hi Prakash,

     

    I got it, thanks! 

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

    hello prakash,

     

    I am facing the same problem, 

     

    DRESP1  1 is not referenced from within a statis subcase.

    This type of response must be specified from within a static subcase.

    This error occurs in MINMAX       2.

     

    I dont know what the issue is, below is the .fem file

     

    $$ optistruct
    $
    DISPLACEMENT(H3D) = ALL
    ENERGY(H3D) = YES
    MINMAX = 1       
    $$------------------------------------------------------------------------------$
    $$                      Case Control Cards                                      $
    $$------------------------------------------------------------------------------$
    $$
    $$  OBJECTIVES Data
    $$
    $
    DESGLB        2
    $
    $
    $HMNAME LOADSTEP               1'normal_modes'       3
    $
    SUBCASE       1
      LABEL normal_modes
    ANALYSIS MODES
      SPC =        3
      METHOD(STRUCTURE) =        2
    $$--------------------------------------------------------------
    $$ HYPERMESH TAGS 
    $$--------------------------------------------------------------
    $$BEGIN TAGS
    $$END TAGS
    $
    BEGIN BULK
    $$
    $$  Stacking Information for Ply-Based Composite Definition
    $$
    $
    $HMSET        2        1 'cons'
    SET     2       GRID    LIST    
    +       1909658   THRU  1909663 
    +       1909999   THRU  1910006 
    +       1909665 1909666 


    $HMNAME DESVARS        1topo
    DTPL    1       PSOLID  73      
    +       MEMBSIZ 15.0    
    +       DRAW    SINGLE   7036745                 7036750                
    +       OBST          72
    $$
    $$  OPTIRESPONSES Data
    $$
    DRESP1  2       volfrac VOLFRAC                                 
    DRESP1  1       com     COMP                                    
    $$
    $$  OPTICONSTRAINTS Data
    $$
    $
    $HMNAME OPTICONSTRAINTS       1cons
    $
    DCONSTR        1       2        0.3     

    DCONADD        2       1


    $$
    $$  OBJECTIVE REFERENCE Data
    $$
    $
    $HMNAME DOBJREF                1'MAX_Comp'
    $
    DOBJREF        1       1       1    -1.0     1.0
    $                                                                               
    PARAM,CHECKEL,NO      
    $$
    $$  GRID Data
    $$
    GRID         501        -369.646-44.6784304.9563                        
    GRID        3709        -210.0  -119.061-19.825                      

     

     

     

     

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

    Hi @iamyasir

     

    Can you edit the file and move the MINMAX below the casecontrol cards section or just above the HyperMesh Tags section?

     

    If this did not work, Is it possible to share the model file?

     

    Please share using the file transfer link in my signature below.

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

    Hey Prakash,

     

    Thanks a lot for your resposne.

     

    I will try moving the MINMAX below the case control section as you suggested.

     

     Other question that i had is, if i can create constraints for stifness in X,Y and Z direction

     

    Below is the optimization setup that i want to run:-

    Objective: Min (Weighted compliance)
    Constraint 1: Volume fraction < Target Percentage
    Constraint 2: Frequency > Targeted Frequency
    Constraint 4: Stiffness in X-direction > Target X
    Constraint 5: Stiffness in Y-direction > Target Y
    Constraint 6: Stiffness in Z-direction > Target Z

     

    Can you please help me in setting up the model.

     

    Thank you

     

    Regards

    Yasir

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

    Hi,

     

    You can constrain the displacement in directions. But I see a conflict with objective and constrains as minimizing compliance is same as increasing stiffness...