LAUSR

Abstract A new form of light steel composite beam has been developed that uses C sections acting in tension with shear connectors in the form of screws or bolts or perforations in the web of the C section. The shear and bending resistance is also increased by using side C sections to the beams. Bending tests on point-loaded beams of 0.8, 1.1 and 1.7 m span showed that for the short span beams, the longitudinal shear bond strength of the base C sections is 1.4 N/mm2 for plain C sections and 2.3 N/mm2 for perforated C sections when expressed over the horizontal plane. Plain side C sections added 80% and perforated side Cs added 130% to the load-bearing capacity of the composite beams with base Cs. The theory is extended to cover elastic design taking account of partial shear connection in which the shear stiffness of the perforated web of the C section is approximately 10 N/mm3 (per unit web area) and that of the plain web is approximately 3 N/mm3.