Incremental dynamic analysis

[nikhilnbr]

i dont know whether my question is correct or wrong,but i have a doubt in the response maxima results
The maximum base shear shown in IDA envelope is not equal to the sum of the forces of the support nodes shown in response maxima
also is there anyway to get the maxinterstory drift vs base shear plot

[z.gronti]

Dear Nikhil,

The response maxima of the supports doesn't happen at the same time for all the supports, hence it is not correct to add the values of different time-load steps. The maximum base shear takes into consideration the values at the same time. That's why you probably don't take the same result. You can get the interstorey drift vs base shear plot in the Hysteretic Curves tab of the Global Response Parameters module in the Post-Processor.

[nikhilnbr]

I have specified ten scaling factors.But after the sixth one its showing unable to apply the next load step.How to fix this error

[nikhilnbr]

Fro the hysteresis tab i can only get the base shear vs interstory drfit for each scaling factor.
is there a possibility to get the max base shear vs max interstory drift plot for the total analysis?

[z.gronti]

Dear Nikhil,

If you carry out a search on this Forum for the term "unable to apply" you should find plenty of posts on this matter.
The Seismosoft's video about solving convergence difficulties might also help you. You may view it in the following links:
https://www.youtube.com/watch?v=p6tAyoofDog
https://www.facebook.com/video.php?v=22 ... =2&theater

Do you mean the IDA envelope? If so, you may find it in the Post-Processor of the program. Otherwise, there is no such diagram for maximum base shear vs maximum intersorey drift.

[nikhilnbr]

can i get the storey shear at each floor level from the results to get a plot of storey shear distribution

[z.gronti]

Dear Nikhil,

There is no such option available in SeismoStruct Post Processor. You may get the storey shear at every floor by processing the results you obtain from the SeismoStruct.

[nikhilnbr]

is it correct to take the frame force of each column (shearforce V3(A)) to get the storey shear.or else can u help me how to find it.

[z.gronti]

Dear Nikhil,

Yes, that is the way of calculating the storey shear, by adding the columns' shear forces in the same axis of the requested floor. Please make sure that you take the correct axis of all the columns.

You may use the group facility also to save time. For more information relative to element and node group facility you may watch the following video
https://www.youtube.com/watch?v=KnyR0j9ehqU
https://www.facebook.com/22301629122752 ... =2&theater

[nikhilnbr]

i am getting a very large storey shear at the bottom storey. is there some problem?