If I am working with a steel where the ratio of min Fy to min Fu is closer
to unity than with the usual structural steel, is this likely to preclude
the section from realizing the advantages of a high shape factor because
the steel ruptures prior to developing ZFy? In my particular case I am
dealing with a steel that is specified as ASTM A572 grade 60, but a special
requirement has been placed on the steel that the min Fy is 70 ksi. I
question whether 0.75 * 70ksi is an appropriate allowable stress.
> From: "Gerard Madden" <GMadden(--nospam--at)mplusl.com>
> To: <seaint(--nospam--at)seaint.org>
> Subject: Re: Shape Factors and AISC ASD
> The shape factor is the ratio of the plastic section modulus Z to the =
> section modulus S ( Zx / Sx ) or (Zy / Sy). It is basically a measure of
> how much inelastic stress you can withstand above and beyond yield.
> Hope that helps.