OptiStruct Error #2866

F. Beinhoff

Dear all,

I want to use measured and filtered acceleration data in the time domain as an excitation load for a model in Squeak & Rattle Director. Therefore, the data have been processed using MATLAB and then have been stored as a .csv file. Furthermore, the sample rate and cutoff frequencies have been adopted to Hyperworks its resolution (100 Hz sample rate, 50 Hz cutoff because of Nyquist theorem & values rounded to 2nd decimal place). 

The import of the data works fine and the plots look as expected. There are no discontinuities at TABLED1 endpoints.

 

However, when running OptiStruct Solver, the Error #2866 occurs (see below). 

Unfortunately, I cannot find this error code in ALTAIR OptiStruct's error message database (to be accessed via Error Message Database (altair.com)). Also, the error message does not provide information that help me with resolving the error.

There is no issue with the model itself as I am working with the official SnRD test model from ALTAIR and the solver worked well with other input signals.

It would be highly appreciated if someone can explain to me what causes the error described and how to solve with it. 

Thank you so much in advance. 

Best, Fabian 

 

Error Message: 

************************************************************************

 A fatal error has been detected during input processing:

  *** ERROR # 2866 ***
  GPFORCE/SPCFORCE/MPCFORCE output is requested for a modal dynamic
  solution. The model has rigid equations and the solution process
  requires multiple eigensolutions. This is not supported in the
  current version.

 *** Run terminated because of error(s) in the input data.

************************************************************************

 ==== End of solver screen output ==== 

 ==== Solver FAILED ==== 

 ==== OptiStruct Job completed ==== 

viniciusgomes

Hi Fabian,

I attached a small video debugging the model, I think it is easier to understand. The model is also attached.

Let me know if you have any other query. 

Thanks,
Fabian

loistf

Does the model run if you don't request forces output?

viniciusgomes

Hello Fabian,

This error happens probably because you have multiple loadcases (multiple eigensolutions) in your deck and requesting GPFORCE output. This is currently not supported. If you have one single loadcase in your model + GPFORCE request, it will run fine. The workaround would be to split your deck into multiple ones, one for each different load case. 

Let me know if this helps. Thanks a lot!
Vinicius

F. Beinhoff

Thanks so much for your reactions ! 

I've unticked the force output and just asked for displacement as an output. 

Furthermore, I did not select X, Y and Z input data simultaneously, but seperately.

Then, I chose the default settings for running OptiStruct Solver:

However, the error (#2866) still occurs: 

 

Did I miss something out ?

Thanks again for your support and your shared insights ! 

 

Fabian 

viniciusgomes

Can you share the .fem file? I can review it for you.

 

Thanks,
Vinicius

F. Beinhoff

Since this is just the demo model, I can share it with you. 

See attached. Thanks a lot ! 

Fabian 

F. Beinhoff

Update: 

When following exactly the same steps and using the same files, now I get these issues after exporting the .fem file: 

The .fem file can though be still exported. When running OptiStruct, now these errors occur: 

 

I never got these issues in advance. This confuses me since I did nothing differently compared to yesterday. 

Best regards,

Fabian

viniciusgomes

Hi Fabian,

I attached a small video debugging the model, I think it is easier to understand. The model is also attached.

Let me know if you have any other query. 

Thanks,
Fabian

F. Beinhoff

Vinicius Gomes said:

Hi Fabian,

I attached a small video debugging the model, I think it is easier to understand. The model is also attached.

Let me know if you have any other query. 

Thanks,
Fabian

Thanks you so much !

Now it is working fine !