Multi-objective topology optimization criteria

- April 23, 2020 at 12:38 pm
  
  ThomasR
  Subscriber
  
  Hello,
  
  For a simple compliance topology optimization problem (in ANSYS Workbench) the criteria is the convergence of this compliance under a given percentage.
  
  But how does it work for a multi-objective problem (compliance + natural frequency)? I read about the Pareto optimal point but does ANSYS use this method?
  
  Thanks,
  
  Thomas
- May 4, 2020 at 9:53 am
  
  Aniket Chavan
  Forum Moderator
  
  ANSYS topology optimization normalizes and combines the objective to a single quantity in case of multiple objective definition. Then, the
  
  optimizer chases the combined objective convergence. Therefore, it is not done through parato optimization.
  
  Regarding the convergance criteria, the % limit means that how much is the % change in the objective value as compared to previous iteration.
  
  If the % change falls in the defind limit by user or default criteria for at least 3 iterations, the solution is said to be converged.
  
  For more details, kindly refer Ansys help:
  
  https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v190/wb_sim/ds_topo_solvers.html
  
  -Aniket
  
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  - September 8, 2023 at 7:44 am
    
    Kushal Joshi
    Subscriber
    
    Hi Aniket,
    
    Is there a way to know how does ansys combine the objectives in case of multiple objectives? Does it use the weighted sum method?
    And in the optimization output we see something as the objective measurement which starts from intial 1.0 and goes down until the convergence. What are these values exactly?
    
    Regards,
    Kushal