An analytical expression to determine "realistic" shear buckling stress in cold-formed lipped channels

Current North American and European design provisions ignore the rotational restraint when evaluating local web shear buckling stresses in cold-formed steel channels. This paper offers a new analytical expression for computing local buckling shear stresses in cold-formed channel members taking into account the rotational restraints imposed by the flanges and the lips. The expression derived is suitable for hand calculations and can replace current code expressions in order to achieve economical steel designs. Comparisons with existing design formulas currently used in practice for the limiting conditions show a difference within 5 %.