ONESTEEL duragal sections

D8.2.1.1 W * L1 - Based on Design Moment Capacity (simply supported beam)
For a beam with full lateral restraint, the design section moment capacity (φM sx ) is used, which for bending
about the x-axis is given by:
φM sx = φ Z ex f y
where φ = 0.9 (Table 3.4 of AS 4100)
Z ex = effective section modulus (see Section D1.2.3.2)
f y = yield stress used in design
For a simply supported beam subject to uniformly distributed loading, the maximum bending moment
(M max ) is given by:
WL
Mmax = 8
where W = total uniformly distributed load
L = length of the beam
Therefore, substituting the design moment capacity (φM sx ) for beams with full lateral restraint for the
maximum bending moment (M max ) and rearranging the equation gives:
Maximum Design Load (W * L1 ) based on the design moment capacity of the beam bending about the
x-axis
Msx
W * L1 = 8φ
L
The equations for the other support conditions are given in Table D8.2.
D8.2.1.2 W * L2 - Based on Design Shear Capacity (simply supported beam)
The design shear capacity (φV vx ) is given in Section D4.2 of the Tables.
For a simply supported beam subject to uniformly distributed loading, the maximum shear force (V max ) is
given by:
W
Vmax = 2
where W = total uniformly distributed load
Therefore, substituting the design shear capacity (φV vx ) for the maximum shear force (V max ) and
rearranging the equation gives:
Maximum Design Load (W * L2 ) based on the design bending capacity of the beam bending about the
x-axis
W * L2 = 2φV vx
The equations for the other support conditions are given in Table D8.2.
DCTDHS/06
DuraGal DESIGN CAPACITY TABLES
MARCH 2002 for STRUCTURAL STEEL HOLLOW SECTIONS D8-3