Dynamic Loads Topology Optimisation in Optistruct

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

Hi,  

The problem consists of a connecting rod submitted to axial loads which define the phases of admission (traction) and combustion (compression). 

I am trying to run the following optimization:      

  • 2 load steps :        
    • Traction        
    • Compression    
  • 2 responses :        
    • Volume        
    • Compliance    
  • 1 constraint :        
    • 60% Volume    
  • 1 objective :        
    • Minimize compliance  

 

I managed to run a direct transient analysis for the two separate load cases. 

I tried running a topology optimization for one of the load cases but an error occured with the following message:  

 

*** ERROR # 557 ***  DRESP1 2 is not referenced from within a static or an MBD SUBCASE. 

This type of response must be specified from within a static or an MBD  SUBCASE. 

This error occurs in DESOBJ 2. 

 

I would like to know:     

  1. How can I create alternating load steps to simulate the traction and compression phases   
  2. If it is possible to run an optimization with these dynamic loads 

 

Thank you !

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @Intan

     

    What type of analysis is it?

     

    Is it possible to share the model file?

    Please use the file transfer link in my signature to share the model file

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @Prakash Pagadala

     

    I've sent the model via the transfer link.

     

    Thank you!

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @Intan

     

    I see that you are using transient subcase for optimization which is not yet implemented. This should be available soon. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    Hi @Prakash Pagadala

    Would you have a suggestion on how can this optimization be carried out?

     

     

    Regards,

    Intan

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018

    One way is converting the time domain to frequency domain and run FRF analysis with optimization.

     

    You can refer to ESLM for Nonlinear Response Optimization on OptiStruct help. Maybe you can try this approach. 

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited November 2018
    Altair Forum User said:

    One way is converting the time domain to frequency domain and run FRF analysis with optimization.

     

    You can refer to ESLM for Nonlinear Response Optimization on OptiStruct help. Maybe you can try this approach. 

     

    Thank you !

    I will try this approach.

     

    Regards,

    Intan

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