Analysis Problems

[Alexandru%20BogdanDeac]

Dear STKO Team,

I am facing convergence problems with the analysis of a rectangular concrete wall. The modeling was made based on the RC Shear Wall video posted on your YouTube channel with some adjustments for this specific model but I think the settings for the analysis are not quite good.

Attached to this message, please find the model.
Please help.

Thank you.

Happy New Year.

Best Regards.

[STKO Team]

Dear user,

We had a look at your file and here is a working copy of your original file:

W-MC-C_5.2.scd.zip

(232.84 KiB) Downloaded 222 times

Here are some changes I made:

• Your model was singular because the top node (control node, where you applied the displacement history) was not attached to the main wall. I added an interaction between the top node (master) and the wall top-edge (slaves), using a rigidLink boundary condition
• I increased the number of time steps. You are using the IMPLEX option in the DamageTC3D model. The IMPLEX algorithm makes the model always converging, but it requires small time steps.
• I changed your cyclic timeSeries. It was incorrectly starting from t = 1. However in your previous vertical analysis you reset the time to 0, so the cyclic timeSeries should start from 0.
• In order to impose a constant dU (displacement increment) for every dT, I changed the abscissas of your cyclic timeSeries, otherwise you waste too much computational time in the first cycles that are pretty small.
• Then you maximum imposed displacement is small. The imposed displacement is 1, and your timeSeries had a maximum of 0.01. So you where imposing a maximum of 0.01 mm. I increased it so that the maximum displacement is 10 mm.
• I also made the total duration of the timeSeries = 1 second (just for clarity, it is a static analysis to the real-time does not matter)
• I also added the monitor tool, that is useful for monitoring your analysis in real-time

Here is the output of your model:

U1.png (128.88 KiB) Viewed 3488 times

U2.png (61.66 KiB) Viewed 3488 times

[Alexandru%20BogdanDeac]

Thank you very much. Yet, the monitor does not run. I get the attached message and the analysis does not go further. If I delete the monitor it is ok.

[STKO Team]

We fixed this problem in version 1.1.5. What version are you using?
Try to download the latest one.

[Alexandru%20BogdanDeac]

1.1.5

[STKO Team]

Yeah you are right,
We fixed it in version 2.0.0 that will be released soon (not in version 1.1.5)

In the meanwhile, here's the fixed "monitor.py" file:

monitor.zip

(4.81 KiB) Downloaded 244 times

You can un-zip it and copy it in
"C:\Program Files\STKO\external_solvers\opensees\analysis_steps\Misc_commands"
replacing the existing one

Let us know if it works.

[Alexandru%20BogdanDeac]

Everything works fine now.

Thank you very much.