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Plot Pushover Curve/Base shear Vs Top Disp Curve

Posted: Fri Oct 16, 2020 8:40 am
by nisaralikhan
Dear STKO team,
Attached please find the RC Bare Frame model. I want to plot the Pushover Curve for which I already assigned two selection sets (Control node top corner and Control nodes base of two columns) and then assigned a monitor in order to plot the Pushover Curve. but when I run the analysis I could not see any plot.
Would you please be so kind to check the model and let me know how to plot Pushover Curve with Monitor option.
Thanking you.
Regards,
Nisar

Re: Plot Pushover Curve/Base shear Vs Top Disp Curve

Posted: Mon Oct 19, 2020 8:40 am
by STKO Team
You don't see anything because the Monitor was places after the pushover analysis. Keep in mind the the monitor start plotting at the exact time you place it in your analysis steps. So I just moved it before the pushover analysis using the Up-Arrow button in the top-right corner of the work tree.

Then there is a problem in the plot. For the X axis you selected the X displacement of the control node, and it is fine. But for the Y axis, you selected the Y Reaction of the bottom nodes, while it should have been the X reaction.
Now since they are reactions, it will have the opposite sign of the pushover force. Since you used a Unit-force, you can plot the pseudo-time in the Y axis, because the pseudo-time in Displacement Controlled analysis, it exactly the load multipler of the reference load. That is, TotalForce = pseudoTime*ReferenceForce. But since in your case ReferenceForce = 1, it means that TotalForce = pseudoTime

I also increased the number of time steps just to make a smoother curve
Here is the modified file:
Bare Frame.zip
(168.5 KiB) Downloaded 12 times

Re: Plot Pushover Curve/Base shear Vs Top Disp Curve

Posted: Mon Oct 19, 2020 1:36 pm
by nisaralikhan
Dear Team,
Thank you very much for your well and detail explanations.
Regards,