HSS beam_load_tables_brochure - Pirate4x4.Com

Foreword
Tables of allowable uniformly distributed loads are presented for rectangular and square hollow structural
sections (HSS) manufactured by the electric resistance welding (ERW) and the submerged arc welding
(SAW) processes. Tables of maximum unbraced compression flange lengths and tables of midspan deflections
for uniformly loaded simple span beams are also included.
The tables of allowable uniformly distributed loads have been calculated in accordance with the 1989
“Specification for Structural Steel Buildings - Allowable Stress Design and Plastic Design” published by the
American Institute of Steel Construction. The allowable uniformly distributed loads are based upon section
property data for HSS that were recalculated in 1996 to account for today’s more precise manufacturing
methods. The recalculated section property data for HSS are published in “Hollow Structural Sections -
Dimensions and Section Properties” available from the Steel Tube Institute of North America.
Tables are presented for two specified minimum yield stress steels - F y = 46 ksi and F y = 50 ksi.
Allowable uniform loads for HSS sizes produced by the ERW and SAW manufacturing methods are presented
in separate tables.
The allowable uniformly distributed loads are based upon the allowable bending stress, F b , equal to
0.66F y and 0.60F y . The allowable uniformly distributed loads for slender sections are calculated in accordance
with AISC “Specification” Appendix B. Slender sections are indicated in the tables with an asterisk
(*) immediately following the design wall thickness parameter and a double asterisk (**) immediately
following the modified value of S x .
The tabulated loads include the weight of the HSS beam which must be deducted to determine the net
load that the beam will support. It is assumed that the load is applied in the plane of the minor axis and that
the HSS beam deflects vertically in the plane of bending only.
Deflections corresponding to the tabulated loads are also given. Deflections caused by actual loading
less than the full allowable load may be obtained by multiplying the tabulated deflection by the ratio of the
actual load to the tabulated allowable uniform load.
Tabulated values of maximum laterally unsupported lengths, L c , of compression flanges of HSS beams
from 1 1/4 inches through 32 inches in width and for varying ratios of M 1 /M 2 are presented for F y = 46 ksi
and F y = 50 ksi specified minimum yield stress steels - see page xx and page xx. The L c values are calculated
in accordance with AISC “Specification” Sections B5 and F3 which specify that the laterally unsupported
length of the compression flange of an HSS beam for which the allowable bending stress may be taken at
0.66F y shall not exceed the value
except that it need not be less than 1200(b/F y ).
(
M
1950+1200 1
) b
M 2 F y
Refer to Part 2, Beam and Girder Design, in the AISC 9th edition “Manual of Steel Construction” for a
discussion of lateral support of beams, beams with concentrated loads and vertical deflection. Symbols used
in these tables follow those used in the AISC “Manual”
Tables of deflections for fully stressed, uniformly loaded simple beams from 1 1/4 inches through 32
inches in depth and for varying span lengths are also included. These tables are presented for allowable
bending stresses equal to 33 ksi (0.66 x 50 ksi), 30.0 ksi (0.60 x 50 ksi) and 27.6 ksi (0.60 x 46 ksi) - see
pages xx - yy. Deflections for allowable bending stress equal to 30.36 ksi (0.60 x 46 ksi) can be obtained by
adding approximately 1 % to the deflection values presented in the table for allowable bending stress equal
to 30.0 ksi.
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