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Fw: Fw: R-values in Seismic Provisions

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Damping doesn't increase the displacement response, period elongation does
(to a point, anyway).

T. Eric Gillham PE

----------
> From: Majid Sarraf <msarraf(--nospam--at)uottawa.ca>
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Fw: R-values in Seismic Provisions
> Date: Wednesday, September 16, 1998 11:26 PM
> 
> 
> I think too much gasoline would burn solid theories of structural
dynamics!
> 
> Based on what theory increase in damping results in increased
displacement
> response? I think the reality and the theory are totally oposite to what
you
> stated.
> 
> 
> Regards,
> 
> Majid Sarraf
> 
> 
> >Just to throw a little gasoline on the fire...
> >
> > There would also
> >be some damping I imagine (which, interestingly, would lead to a higher
> >maximum displacement).
> >
> >It would seem reasonable, in my mind, that the above factors
(overstrength,
> >period elongation, damping) would drop the R factor down from 2.2 to 2.
> >
> >So, at least according to UBC97, it would seem that an R factor of about
2
> >is appropriate for an "elastic" response, at least the way I see it. 
> >Anyone agree/disagree?
> >
> >T. Eric Gillham PE
> >
> >
> 
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