Can only run analysis even though i have set it up for optimization in the optistruct run options ?

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

Good evening

 

I am currently facing issues with my model. It only seems to run analysis even though i have set it up for optimization. I have double checked everything that i set-up in my topology, responses, constraints and objectives as well. 

 

I have also double checked that my input is Analysis>Optistruct>Run Options>Optimization.

 

But the file only runs for an analysis. It doesnt go ahead and remove all the material as it generally does in optimization. 

 

Any help would be highly appreciated.  

 

Thank you

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2015

    I have a max displacement constraint set up with upper bound as 0.5 and set up objective as minimum volume to reduce mass. My responses include displacement and volume. Also my topology is set-up for the design space with a property for itself called design. 

     

    OPTIMIZATION PROBLEM PARAMETERS :

    ---------------------------------

     NO DESIGN MATERIAL OR DESIGN VARIABLES FOUND  : ANALYSIS ONLY

       ------------------------

       Static Subcase Summary :

       ------------------------

       ----------   --------  --------

       Subcase ID    SPC ID   FORCE ID

       ----------   --------  --------

            1            1            2

       ----------   --------  --------

       Run Type                        :   Analysis Only (No design elements)

     

    This is the message in the screen out file and it only runs an analysis then. 

  • Rahul_P1
    Rahul_P1
    Altair Employee
    edited June 2015

    please send us the file using the dropbox below

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Do you have a solution to this Rahul? I am currently experiencing the same problem

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Hi GeorgeB,

     

    Can you check whether the Export options is set to All in OptiStruct?

     

     

    <?xml version="1.0" encoding="UTF-8"?>post-7616-0-33508900-1444200947_thumb.jp

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Yes I've tried 'all' and 'displayed' but both don't work. While it's processing, the feedback text at the bottom left of the screen says '0 elements processed', '0 CTETRA elements processed', '0 nodes processed' and other messages including an error message but they pop-up too quickly to read.

     

    I am trying to simply follow this tutorial (http://training.altairuniversity.com/optimization/topology/toplogy-optimization-basic/) but for a PSOLID instead of PSHELL. I have watched all the videos twice and still can't find out the problem with my model.

     

    It just gives me results for an analysis instead of optimization

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Hi GeorgeB,

     

    could you please share the model and .out file using the dropbox link in my signature below?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Hi Prakash, Sorry for the delay, I've sent the files now

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Thanks George, 
     

    I will have a look at it and I will update to you soon.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2015

    Hi Goerge,

     

    I think the problem is with the material. 

     

    You have a mass response in your optimization set up and no density is provided for the material.

     

    Please provide material density and check.

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

    Hey,

     

    I am sorry to pull up this old thread again, but I have the exact same problem. I set up my simulation with all the components, Load Collectors, Load Steps, Constraints, Objectives, Responses and the material is completely set up. Still, OptiStruct will only perform an analysis and no optimization.

    I double checked everything and even rebuilt the same model again from scratch. Same problem.

    Could you help me please?

     

    I sent my project folder to your DropBox TransferLink.

     

    Thank you very much!

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited July 2017

    Hi Kensei,

     

    Make sure you changed the run option from Analysis to Optimization in Analysis Page>> OptiStruct

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited July 2017

    Yes, I changed the option to Optimization. Then back to analysis just to be sure and then back to Optimization. Still no change. Does it work on your machine when you change the setting to optimization?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited July 2017

    Hi @Kensei

     

    I just saw the model and I see that there is no design material specified (DESVAR) in your model. Please do specify the Design variables for optimization. You can refer to optimization tutorials available on help. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited July 2017

    Hey,

     

    sorry for the late reply. Yes, that was it, thank you very much! I must have just overlooked it or not confirmed it with 'create'.