Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: EBF's

[Subject Prev][Subject Next][Thread Prev][Thread Next]
> If the nominal strength is 36 ksi for link beam and for bracing,
> increasing 50% the force in bracing is similar to thinking that the link
> beams have equivalent strength of 36ksi x 1.5=54 ksi.  It is not
> inconceivable that the steel supplied for the link beam could be dual
> cert or A36 having actual strength higher than 54 ksi, since ASTM do not
> have upper limit for Fy.  Should this be the case then the link beam may
> not yield first as designed.
> 
> Y. Henry Huang                  
> 


We encountered this problem in our office several months ago.  Our solution
was to check around with a few steel suppliers and find out what Fy we
could expect.  Turns out that 36 ksi in Northern California will yield at
around 60 ksi  (58 ksi was the number all the suppliers we contacted were
telling us.)  We ran our analysis, and then sized all connections and
bracings members assuming the link beams had a yield strength of 60 ksi.

The debate in our office now is whether or not we should just spec Grade 50
steel for all beams and columns, since A36 doesn't really exist in our
area, its all dual cert, as Henry points out.  Seems that steel mills
figured the stronger the better, so if we ask for 36 ksi yield and the give
us 80 ksi we should be really happy about it.  Our problem is when we
*want* the steel to yield, like EBFs or moment frames.

Paul McEntee