IDA curves

[andresr]

Hello

I am trying to perform an Incremental dynamic analysis in Seismostruct but i am not sure how to obtain the IDA cuves with the Max inter-story drift in the X-axis and Spectral acceleration in the Y-axis and then i need to export these results to Excel. Does anybody know how to do this??.

[z.gronti]

Dear andresr,

The IDA Envelope is visible in the Post-Processor when Incremental Dynamic Analysis has been carried out, where it is possible to plot (i) the
maximum relative displacement versus the peak base shear value found in a time-window around the maximum drift (Corresponding Base Shear), (ii) the maximum relative displacement versus the maximum base shear value recorded throughout the entire time-history (Maximum Base Shear), or
(iii) the maximum base shear versus the peak relative displacement value found in a time-window around the maximum shear (Corresponding Drift).

All the abovementioned refer to the same direction for the displacements and base shear values, which is the direction of the applied acceleration. If you are interested in getting these values in different directions, then you should get them from the Global Response Parameters tab, by making the proper selection to get the displacement values in the Structural Displacements tab and the proper selection to get the Base Shear in the Forces and Moments at Support. You may copy the results and Paste them to Excel for further process.

[obaidullah khan]

Hello my question is regarding the time window option in the pre processor IDA parameters. what is criteria for defining the value in the time-window option, as i selected the default 0.5 value for my IDA analysis and the software is not showing me the IDA parameters (max drift, displacement, base shear etc. ) in post processor...plz explain briefly as not too much detail in manual regarding time window option. for instance if scaling is from 0.1 to 2.0 what should be the time window value for that. hope you understand.

[seismosoft]

This time-window is what exactly described in the program label and in the manual. It is the time window (t-0.5sec ... t+0.5sec) before and after the maximum displacement, within which the program searches for the maximum base shear. This is because these two rarely coincide in exactly the same time step.
The range depends on the record and the structure that you are employing, but 0.5 sec is a reasonable value. To the best of our knowledge there are no guidelines in the literature for its definition. You should decide it yourself or maybe with your supervisor.
Seismosoft Support