Chord rotation for ductile mechanisms

[DanieleArcuri]

Good evening. I would like to ask you how couli i extract results to perform a chord rotation verification of ductile mechanisms after pushover and/or non-linear time history analysis.

Thank you for your great job!
Daniele

[STKO Team]

It depends on the element that you use, but most beam elements should support the "chordRotation" output.

FB Chord.png (114.87 KiB) Viewed 2257 times

[DanieleArcuri]

okok, thanks a lot for the answer. Therefore, to do so, should i go to the custom element results in the analysisStep Editor inside the pre-processor window, right? I'm saying this since that chordRotation output is not mentioned in the built-in ones and i don't know otherwise how could i do.

I hope you could provide me the answer because i just started with STKO (less than 1 month) and if i will solve this problem i think i will move to the accademic version to run a lot of analysis for my Ph.D.
Have a good day,

Daniele

[STKO Team]

Sure, in the MPCORecorder, go to "custom element results" and add the string you want.
We did this because in OpenSees, for element-based results, you may have potentially an infinite number of possible results.
Therefore we created built-in choices only for the most-commonly used ones.

[DanieleArcuri]

Dear STKO teams, thank you so much for your answer.

Best regards,
Arcuri Daniele

[DanieleArcuri]

I apologize once again for the disturb, but I would like to ask why, once I have obtained the results for the chord rotation in the Post-process window, I don't have the possibility to extract the data to perform verifications using the chart data functionality. I attach on the following my STKO file.

[DanieleArcuri]

Good morning,

During my conversation with Dr. Petracca, I understood that for extracting the chord rotation results, it is important to note that these results are stored at the element nodes rather than at integration points. Therefore, they cannot be extracted using the "extract chart data" command available in the post-processing window.

I tried searching the old forum discussions to find a Python script for extracting the results. I came across a script called "make_chart_ele_nodal_results," but I didn't fully understand how it works since it seems to allow extracting results for only a single element, rather than all elements in the structure. How can I proceed? Your assistance would be greatly appreciated. If needed, my STKO file is provided in the previous response.

Thank you very much, and have a great day.

Daniele

[STKO Team]

That script can be adapted to your needs, but it depends on what you want to achieve.
In that example is the user that manually puts the ID of the element for the extraction. Then STKO extracts data for that element and makes the chart data.

Another option would be to do automatically the same for all elements (or for all selected elements), but then it would be convenient to save those results on a text file.
Then you have to decide if you want to save results for a single time step, or for all time steps.

Therefore you should first decide the output format of your data, then we can play with the script to produce those data