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Hello,

My building inventory is in a Low-Code/Pre-Code zone and when I run a Shakemap Scenario, the fragility groups are not assigned properly. This is giving me a "No results to import!" message since there are no fragility groups for URM buildings in High-Code zones, per HAZUS' methodology. How can I make sure that the buildings are assigned to the correct zone?

I appreciate your help.
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Uncertainty Quantification (quoFEM) / Re: QuoFem Parameter Estimation
« Last post by STOKLJOS on January 07, 2022, 11:05:15 PM »
Hello,

Thank you for your reply. I also noticed the large difference in max strength. This is due to the error function looking at largest loads when pushed in the opposite direction as well as the normal direction. I fixed that so the output is always positive but still running into the same local minima solution so I will try the steps you laid out.

Thanks again,

Josh
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Uncertainty Quantification (quoFEM) / Re: QuoFem Parameter Estimation
« Last post by AakashBS on January 07, 2022, 10:59:09 PM »
Hello Josh,

By observing the results, we think there could be two potential issues:

1) The model might not be numerically stable (going by the large changes in the MaxStrength residuals for small changes in the parameter values, as seen in evaluation 2 vs all the others).

2) A gradient-based (i.e., local) optimization algorithm is used to perform parameter estimation. This algorithm works for continuously differentiable objective functions and will converge to a local minimum. It seems that there are multiple minima even in a very small range of the parameter values (caused by noisy MaxStrength results) - see attachment. That is why the algorithm is taking small steps and converging to a local optimum in the vicinity of the start point of the search.

We recommend that you first perform a parameter study (for e.g. forward propagation using LHS in quoFEM) to identify any such discontinuity/noisiness in the model outputs before performing a parameter estimation study. Sometimes the noisy behavior indicates that the model can be improved (for example by setting stricter convergence tolerance, if feasible). If this is not feasible, you can perform a Global Sensitivity Analysis using quoFEM and decide to not calibrate the values of parameters that are causing this noisy behavior, provided that parameter has a low sensitivity index. If the output is sensitive to the parameter which is causing the noisy behavior, then your option is to use a global parameter estimation method. Currently, you can use the TMCMC algorithm in quoFEM to perform probabilistic parameter estimation, which works for such noisy landscapes too. The trade-off is that it will require a large number of model evaluations, in comparison to a local search method. But you can use DesignSafe's computational resources to overcome this issue. In the future, we might make other global deterministic parameter estimation methods available in quoFEM.

P.S. Please double check if the MaxStrength values are being returned correctly. We ran simulations with the model script that you had previously shared with us over a large range of the parameter values and the MaxStrength residuals were around -4.

Thanks,
Aakash and Sang-ri
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Uncertainty Quantification (quoFEM) / QuoFem Parameter Estimation
« Last post by STOKLJOS on January 06, 2022, 11:23:03 PM »
Hello,

I have been using the parameter estimation for an opensees model and it seems to not yielding the best results. For instance look at the output of the dakotaTab.out; the parameters are varying by 1e-4 and the best parameter picked is 30 kips over the experimental value. I am currently using a convergence tolerance of 0.0001 and max iterations of 1000. The parameters also have a healthy lower and higher bounds on them (ie stc has lower of 0.01 and higher of 1).

 I am wondering why the simulation is yielding results after 7 evaluations and not varying the parameters more to hopefully converge to a closer result.

Thanks,

Josh




%eval_id  interface stc                srs            shr                  MaxStrength   
1        NO_ID     0.3                   0.33           1                     -159.9473689   
2        NO_ID     0.3001011366   0.33           1.000231482    30.27846112   
3        NO_ID     0.3001254848   0.33           1.000312594    -158.1980189   
4        NO_ID     0.3001035714   0.33           1.000239593    -153.3980689   
5        NO_ID     0.3001013801   0.33           1.000232293    -159.5161689   
6        NO_ID     0.300101161    0.33           1.000231563    -155.7201689   
7        NO_ID     0.3001011391   0.33           1.00023149     -157.0393689
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Uncertainty Quantification (quoFEM) / Re: quoFEM with OpenSees SP
« Last post by fmk on December 23, 2021, 08:24:31 AM »

There might be, though it will be a convoluted way as it would involve using the OpenSeesPy option to launch OpenSeesSP and would require you to modify the way your script work. I am checking with someone who has used quoFEM, dakota and a different parallel application running at TACC to see how he did it.
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Uncertainty Quantification (quoFEM) / quoFEM with OpenSees SP
« Last post by rsam1993 on December 22, 2021, 09:25:32 PM »
Dear all,

I am working on a long-span 3D bridge model and since the model is large, I prefer to use OpenSees SP as an interpreter to run the analysis with quoFEM. Is there any way that I can do it using my local machine or Design-Safe supercomputers?


Best,
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Performance Based Engineering (PBE) / Re: Damage and loss results are not available
« Last post by adamzs on December 05, 2021, 07:39:10 PM »
Hi Scott,

Thank you for reaching out to us, I will help you figure out what goes wrong in the simulation.

The error you received could stem from a problem in the OpenSees simulation or in the damage and loss assessment. First, I suggest excluding the possibility of an OpenSees issue.

Please navigate to your working directory (C:/Users/KPP/Documents/PBE/LocalWorkDir), then go to the tmp.SimCenter folder and you should see a log.txt file there. If you shared that txt file here, it could help me a lot in understanding the issue better.

Thank you,
Adam
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Performance Based Engineering (PBE) / Damage and loss results are not available
« Last post by scott110 on December 04, 2021, 01:06:02 PM »
Hi
I have used PBE Application for a 4-story RC dual building with only one random variable under 40 earthquake records. After analysis is done, Igot thr following Error Damage and loss results are not available.
Can you help me how I can solve it?

6:21:05.539 Debug: WorkflowAppWidget::errorMessage "Loading Loss Results" ()
16:21:05.541 Debug: "Loading Loss Results" ()
16:21:05.549 Debug: WorkflowAppWidget::errorMessage "Could not open file: C:/Users/KPP/Documents/PBE/LocalWorkDir/tmp.SimCenter\\/DL_summary_stats.csv . Damage and loss results are not available." ()
16:21:05.551 Debug: "Could not open file: C:/Users/KPP/Documents/PBE/LocalWorkDir/tmp.SimCenter\\/DL_summary_stats.csv . Damage and loss results are not available." ()
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thank you for your reply,

We decided to use PBE to investigate the effect of isolator on the overall
probability of collapse and also to UQ engine

the Backward compatibility and keeps old files works is also a priority.

Anyway, I figured out the solution of my question,
it was simply to set a bool variable out of (if --getRV) scope not inside in MDF_SAM script

after few weeks I will finish all required extensions,
Organizing a Zoom meet to hear a feedback could be great.

Thank you again,
Ahmed Maky
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Thank you for the additional information.

As far as I see, you are interested in structural response estimation. The extensions you propose to the StandardEarthquakeEDP and MDOF tools are great and they would be appreciated by other members of the research community.

I have a few suggestions:

- As long as you focus on EDPs, it would probably be easier to use the EE-UQ tool instead of PBE. PBE adds an extra step to the workflow that you don't seem to use now. Once you have the extension with the new EDPs and base isolator added, you will be able to return to PBE and take advantage of those changes.

- Our office hours have been superseded by live expert tips that we hold every Friday. They include a presentation (the tips) and an open discussion around that topic afterward. Our next EE-UQ presentation is a few weeks out, so I suggest continuing the discussion here and perhaps setting up a Zoom call if needed.

First, I suggest you look at EE-UQ, try to run the workflow there, and let me know how that goes. If the individual modules work, EE-UQ should also run well.

Adam
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