# Shear capacity (Beams: AS 4100)

The shear check is performed according to AS 4100 Clause 5.11.

For rolled and welded I- and H-sections, and for Channel sections, an approximately
uniform shear stress distribution is assumed when calculating major axis shear
capacity (to Clause 5.11.2). For these same sections a non-uniform shear stress
distribution is assumed when calculating minor axis shear capacity (to Clause
5.11.3), with a shear stress ratio f*_{vm} / f*_{va} = 1.5

For hollow sections a non-uniform shear stress distribution is assumed when
calculating both major and minor axis shear capacity (to Clause 5.11.3). For a CHS
section the nominal shear yield capacity is taken per Clause 5.11.4, while RHS and
SHS sections assume a shear stress ratio f*_{vm} / f*_{va} = 3 * (2
* b + d) / [2 * (3 * b + d)] for major axis shear capacity and f*_{vm} /
f*_{va} = 3 * (2 * d + b) / [2 * (3 * d + b)] for minor axis shear
capacity.

## Shear buckling

For rolled and welded I- and H-sections, and for Channel sections, about the major
axis, and also for RHS and SHS sections about both axes, when the shear panel depth
to thickness ratio exceeds 82/√(f_{y}/250) then the shear buckling capacity
will be calculated per Clause 5.11.5.1 assuming an unstiffened shear panel.

Note that for rolled and welded I- and
H-sections, and for channel sections, f_{y} will be taken as the yield
strength of the web based on t_{w}.