Incremental Dynamic Analysis (PGA vs Drift)

[JRCM]

Greetings!

I am performing incremental dynamic analysis (IDA) in order to obtain the fragility curve of my structure. I intend to plot the peak ground acceleration (Y-axis) vs Drift (X-axis). Is there any way to do this in the software?

Thank you!

[z.gronti]

Dear JRCM,

The requested plot is not automatically created in SeismoStruct. You may take the drift values from SeismoStruct and create the diagram in a spreadsheet application.

[JRCM]

Dear z.gronti,

How do I get the peak ground acceleration (PGA) value corresponding to the drift value? Is this done by using the scaling factors (ex: 0.5 scaling factor = 0.5 PGA)? Does this mean that I need to get the drift values every scaling iteration?

Thank you!

[seismosoft]

Yes, you need to get the drift time-histories for each scaling factor separately.
Seismosoft Support

[ESTRUCTO]

Hi.

I am performing an IDA analysis to a 4 levels regular plane concrete frame. I have an issue to considering the damping that I must use. I have defined infrmFBPH Element Class to beam and columns elements, but I note that there is a DAMPING button to define the values. After, in the SETTINGS menu there is a DAMPING option with other values to define. The first one is the HYSTERETIC DAMPING and the second one is the NON-HYSTERETIC damping. My question is about what is the correct way to consider the damping in the IDA analysis? Do I have to define damping in both options? I have used Rayleigh damping with the initial analysis with tangent stiffness.

Thanks a lot.

[huffte]

I will direct you to the excellent online resource at the link below, from which the ensuing quotation is taken:

https://help.seismosoft.com/seismostruc ... rmfbph.htm

"In this element's dialog box it is also possible to define an element-specific damping, as opposed to the global damping described in here. To do so, users need simply to press the Damping button and then select the type of damping that better suits the element in question (users should refer to the Damping menu for a discussion on the different types of damping available and hints on which might the better options). Users are reminded also that damping defined at element level takes precedence over global damping"