Learning Forum

[Aaron Johnson]

I am trying to run a topology optimization for a part, however I keep getting the following message.

"the optimization solution run was terminated. check the solver output on the solution information object for possible causes"

I then open the "Open Solver File Directory" to view if I am getting any error files or issues.

I have a topo.err file that says the following.

*** WARNING *** The optimization problem cannot be solved. Please reformulate your problem. *** ERROR *** MAPDL solver terminated unexpectedly with error code 99. For more information check solver output. *** WARNING *** File 'numCPU.dat' not found.

Below is the topo.out file.

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

 ----------          Welcome to Topology Optimizer          -----------

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

       Version 2022 R2 (Build: 194) from 20220527

       Copyright 2022 ANSYS Inc. All Rights Reserved

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

       Execution time: Sun Jul 23 13:45:59 2023

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

   Parameter setting:

      solver                   = Scpip

      ansys version            = 2022 R2

      design elements          = OptimizationRegionElements.dat

      feedersystem list:

       - Static system 'Static25' with id 25: 1 load case(s) at t = 1

      filter mode              = 1

      penalty parameter        = 3

      minimum member size      = 0

      maximum member size      = 0

      minimum density          = 0.001

      initial response scaling = yes

      boundary padding         = true,bounds,vol

      restart information      = final

      mapdl ncnv               = 1e+12

      maximum iteration        = 500

      acc                      = 0.001

      units                    = MPA

      output frequency         = 1

      max intermediate files   = 500

      dynamic max approach     = true, 0.9

      objective 1              = single compliance (force load) for load step 1 of feeder system 'Static25' [1]

      constraint 1             = total mass with lower bound 60 and upper bound 60

      constraint 2             = global equivalent (von-Mises) stress for load step number 1 of feeder system 'Static25' with upper bound 227.273

      method                   = SCP

      acc scp                  = 1e-06

      version scp              = 402

      cut off in scp           = 1

      linear inequalities remain in active set in scp = selected always

      initial penalty scp      = 1

      move limit scp           = 0.5

      asymptote strategy       = program controlled

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

   Start generating constant data...

   ...done

   Start generating tree...

   ...finished.

   Start generating element neighborhood...

    10 Percent done

    20 Percent done

    30 Percent done

    40 Percent done

    50 Percent done

    60 Percent done

    70 Percent done

    80 Percent done

    90 Percent done

   100 Percent done

   ...finished.

 Determine regions where minimum member size cannot be satisfied.

   Starting MAPDL...

 *** WARNING ***

 The optimization problem cannot be solved. Please reformulate your problem.

 *** ERROR ***

 MAPDL solver terminated unexpectedly with error code 99. For more information check solver output.

  FINAL SUMMARY

  -------------

  Total number of model evaluations: 0

  Objective(s):

    [  1] Name: Objective

          Value : 1.79769e+308

  Constraint(s):

    [  1] Name: Mass Constraint_64

          LB: 6.00000e+01 <= Value: 1.79769e+308 <= UB: 6.00000e+01  Deviation: inf %

    [  2] Name: Global Stress Constraint_71

                             Value: 1.79769e+308 <= UB: 2.27273e+02  Deviation: 7.90985e+307 % NOTE: This is an approximation to the actual value: 0.

 *** WARNING ***

 File 'numCPU.dat' not found.

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

 --> Topology Optimizer finished with errors

     Total time:  0h 2m 1s

     CPU time:    0h 0m 0s

     Peak Memory: 172968 K

     I/O Read:    48568849 Bytes

     I/O Write:   928365 Bytes

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

Below is the solve.out file.

 *** FATAL *** Attempt to run ANSYS in a distributed mode failed. The Distributed ANSYS process with MPI Rank ID =    1 is not responding. Please refer to the Distributed ANSYS Guide for detailed setup and configuration information.

I have looked at some other forums, but I can't seem to figure out the issue.

I don't know if I need to change someting in the "Advanced Properties" in the "Solve Process Settings".

[Lydia Lymperopoulou]

Hi Aaron,

Are you sure you are correctly modeling your problem? I suggest you follow the steps demostrated in this course Topology Optimization in Ansys Mechanical | Ansys Innovation Courses

[Aaron Johnson]

Thank you for the response. I ran the Ansys innovation courses file you suggested and ran into a similar problem. I generated the same error message.

"The optimization solution run was terminated. check the solver output on the solution information object for possible causes"

Association: Project>Model>Topoogy Optimization>Solution

 

 

It gave me an topo.err file, but nothing was in it. It also gave me a solve.out file that says the following.

 *** FATAL ***
Attempt to run ANSYS in a distributed mode failed.
  The Distributed ANSYS process with MPI Rank ID =    1 is not responding.
  Please refer to the Distributed ANSYS Guide for detailed setup and configuration information.

 

The only thing that I could not do was to make sure to turn on "level set method topology optimization" as it was not in my options.

The file that I'm trying to recreat is in the following video as it is for my class. ANSYS 18.1 Topology Optimization - YouTube

[John Doyle]

It looks like the solution is drifting toward infinity somewhere.  

Is it just this model that is giving you this error?  Can you try a simpler test problem?

[Aaron Johnson]

I tried to do the Ansys Innovation Course above and I did not get the system to work again. This is my first time running the topology Optimization. I have tried a few difference test problems, but I get similar results.

[Daniel Lim]

I am experiencing the same error as Aaron with the objective value stating the same value: 1.79769e+308. Is there an update to this issue?