response spectrum analysis 2

[executives]

A response spectrum analysis can be used in seismic design of structures.
My question is if the structure is built with thin gage cold formed panels and members would the analysis be accurate, assuming that non-linear behavior would be present due to large deflection?

Thanks

 

[JStephen]

It's my understanding that it is assumed that non-linear behavior will occur in most seismic design- even though it may not be included specifically in the analysis. If the item in question is some sort of standard structural item, use of the proper "R" value should account for the general behavior. If it's some sort of odd item that isn't included in building codes, perhaps it would be a different situation.

Perhaps more specific information on the type of structure would get more specific answers.

 

[cbrn]

Hi,
the fact is that, for spectrum response analysis, most of the programs (even hi-end ones) can't take into account any non-linearity. This limitation falls off if you shift from the frequency domain to the time domain, thus performing a full-transient analysis. But the "conversion" from an excitation acceleration spectrum to a time-vaiant displacement history can be VERY problematic. You could use IDFT if you had the accel amplitude AND phase spectra, or perhaps you can use a randomic distribution of phases throughout the frequencies...
Anyway, if the code you are using explicitly states that it handles non-linearities in a spectrum response, then I'd say it's almost certainly as accurate as if it was to operate in the linear field.

Regards