The American Petroleum Institute's API RP 2A (Working Stress Design, same as ASD,
and LRFD versions) have formulae permissible stresses / interaction formulae for
strengths for round HSS sections. These are being used by the offshore industry
around the world for over two decades. The offshore structures consist primarily of
round HSS (we call them tubular) members. It covers the reduction in strength for
high D/T ratios quite well and is an industry standard.
Bill Polhemus wrote:
> Hey, Davis, this brings up (again) a point that needs to be reiterated:
> The Design Specification for HSS members is GREAT, in and of itself a good
> reason to spring for the purchase of one of these manuals if you do much design
> with HSS.
> But it ONLY comes in the LRFD flavor, and as you point out, the methodology is
> sufficiently unique to HSS that I don't believe you could "wing it" by applying
> the AISC-ASD Design Specification to these members.
> I haven't tried--I've only used the HSS Design Spec a few times, for column
> design--but I'm sure someone could "convert" the HSS LRFD formulae to ASD, but
> to me this was yet another nail in the ASD coffin. I'm surprised that no one
> here has complained about this (that I can recall).