Incremental Dynamic Analysis

[ydnar_rye]

Thank you for the response Admin.

What I mean is from the results of post-processing->IDA Envelop->Max Drift vs. Corres. Base Shear, how can I make my IDA curves (Sa of T1 5% vs. Max. ISD Ratio)?

Thank you again for your further reply.

By the way, I know that the video I posted was not created by Seismosoft since I cannot find any sample video provided by Seismosoft regarding IDA procedure.

[seismosoft]

I am not sure what you mean with 'Sa of T1 5%'. The IDA curves are the ones provided by the program. Again we are not sure what you mean, but if you mean the transformation in the ADRS (acceleration-displacement response spectra) space, this is not done automatically by the program.
Seismosoft Support

[ydnar_rye]

What I mean for Sa of T1 5% is the first-mode spectral acceleration with 5% damping coefficient. This is the vertical axis (as the Intensity Measure where other researchers use PGA instead of Sa,T1 of 5%) plotted against the horizontal axis of maximum interstory drift (Demand Measure, DM) for a typical IDA curves, as indicated in the paper of Vamvatsikos. Maybe, I need to review again the plots of IDA Envelope from Seismostruct. Thank you again for answering.

[seismosoft]

Indeed, this is what I suspected.
As we explained in our previous post the transformation in the ADRS (acceleration-displacement response spectra) space is not done automatically by the program.
Seismosoft Support

[obaidullah khan]

hello everyone:
In doing IDA I use IDA parameters e.g. start with 0.25, end at 1.5 with scaling factor 0.25. so in post-processor I should have a total analysis results of 6 at (0.25,0.5,0.75,1.0,1.25,1.5) but in my case i am unable to get results on these scaling factors instead i got values like
[Analysis No.1 - scaling factor:0.25,
Analysis No.4076381 - scaling factor:7.702905,
Analysis No.0 - scaling factor:4.7379E,
Analysis No.0 - scaling factor:1.03346,
Analysis No.12578816 - scaling factor:-6,
Analysis No.0 - scaling factor:1.684174]
and so on in this way a total of 67 analysis results are obtain instead of 6 but non of them are correct and not giving/showing the true results. Even though i am applying a single matched accelerogram in a single program file. Why is it so, what can be the reason plz explain?

[z.gronti]

Dear obaidullah khan,

Could you please check if you use the current version of SeismoStruct v2024-Release 2-Build 30? If so, please check the selected parameters in the IDA Parameters tab of the Pre-Processor.

[obaidullah khan]

i am using Seismostruct v2024 Release-2 Build-1.
and as far as IDA parameters are concern i am using start scaling=0.10 end scaling 2.0,sacling factor step=0.20.in IDA envelop one ground node and one top story node is selected. Considered direction= X. Time window=0.50

[z.gronti]

Dear obaidullah khan,

Please download the current version of SeismoStruct v2024-Release 2-Build 30, run the project with the current version, and let us know if you still receive the same behaviour. If you do so, please send us your model to check it.

[obaidullah khan]

Dear z.gronti,

I have downloaded the latest version of SeismoStruct v2024 release 2-Build 30 and run the IDA analysis again, but unfortunately got the same response ( errors in post-processor ) as i mention in my above first post.

[seismosoft]

Can you please send us the input file at support@seismosoft.com?
Thanks
Seismosoft Support