quoFEM Pinching4 Opensees Material Calibration

[Dano]

Hi


I try to calibrate the pinching 4 model  and i used the example in the the website and replaced my data in the strain and stress file. but i got this error "No dakotaTab.out file - dakota failed .. possibly no QoI " would you please help me solve it.

There was a post for that already but it wasnt solved:
https://simcenter-messageboard.designsafe-ci.org/smf/index.php?topic=226.0


Thanks for your time and consideration

[AakashBS]

Hello,

Could you please share the dakota.err file from the 'tmp.SimCenter' directory?

Best,
Aakash

[AakashBS]

Hi,

Here are a few recommendations:

1) Please remove the space after "Pinching" in the name of the file "Pinching Material.tcl".

2) Please use a different initial point for variables. When you set the initial point to 0 for the parameters of the Pinching4 model, the backbone curve is not uniquely defined and the material model cannot be evaluated.

3) Are you using the strain or the stress values as data for calibration? Please double check the name of the calibration data file in the UQ panel of quoFEM to make sure you are providing the right file. If you would like to use the stress instead of the strain, please make sure that the stress data is in one row, if the data is from one test.

Best,
Aakash

[Dano]

Hi,

thanks a lot for the quick reply.

I corrected the files for the strain and stress values and have the same format as in the example qfem-0018.
I also kept the names of the files "calDataField.csv" and "stress.1.coords".

The only thing i changed in the "matTestAllParamsReadStrain.tcl"-file is the material

uniaxialMaterial Pinching4 1 $ePf1 $ePd1 $ePf2 $ePd2 $ePf3 $ePd3 $ePf4 $ePd4 $eNf1 $eNd1 $eNf2 $eNd2 $eNf3 $eNd3 $eNf4 $eNd4 $rDispP $rForceP $uForceP $rDispN $rForceN $uForceN $gK1 $gK2 $gK3 $gK4 $gKLim $gD1 $gD2 $gD3 $gD4 $gDLim $gF1 $gF2 $gF3 $gF4 $gFLim 99999 cycle;

I checked the Initial Points and used the backbone to get values for the "RV".

Unfortunately I get an error again.

EVAL CONCURRENCY: 16
CWD: E:\04_Software\quoFEM\03_Directories\LocalWorkDir\tmp.SimCenter\templatedir
running Dakota:  dakota -input dakota.in -output dakota.out -error dakota.err
RUNNING DAKOTA ERROR:  b''


         dakotaTab.out not found. Response.csv not created.
         -----------------------------------------------------------------------

16:36:20 - Dakota Calibration Processing Results
16:36:20 - No dakotaTab.out file - dakota failed .. possibly no QoI
16:36:20 - Analysis complete

I will put the .txt data in the attachment.

Thanks a lot for your support.

[AakashBS]

Hello,

Thank you for providing the corrected files.

When I open the shared json file in quoFEM and try to replicate your analysis, I see that the analysis is running. However, I get an error as shown in the attached screenshot - the size of the strain data is one less than the size of the stress data. Please see if fixing this discrepancy resolves the issue.

In order to troubleshoot your problem setup more effectively, I suggest reducing the number of stress-strain data points. For instance, you can consider keeping every 100th point. By doing so, the analysis will finish more quickly, allowing you to identify any potential errors with greater efficiency. Once you are sure the problem is setup correctly, you can use the entire dataset to get final results.

[Dano]

Hi AakashBS,

thanks a lot for your support. You guys are amazing.

I checked the files again. As you said the numbers of values were not equal so i corrected that. Still it didnīt work.

So i followed your advise and shortened the values of my experimental data. Instead of choosing every value, i only choosed each 100th value so I got the total number
of 992 values. This works just fine.

Again, thanks a lot for the quick support and wish you all a great weekend.

Best Regards,
Dano

[Dano]

Meanwhile, the tool is working for me. However, I am not getting the expected results.

The goal of my task was to determine the parameters of the Pinching04 model to achieve the same hysteresis behavior as in my experimental attempts. For this purpose, Bayesian Calibration or Deterministic Calibration can be chosen.

However, I am not obtaining the desired results. In the attachment, you will find the comparison with the test results.

Do you have any tips on how I can obtain the parameters to achieve these results?

[AakashBS]

Hello Dano,

Glad to know that the analysis is running. For a more detailed discussion, could you please attend the UQ Office Hours (https://simcenter-messageboard.designsafe-ci.org/smf/index.php?topic=231.0)?

Best,
Aakash