Compression Tests of DuraGal Angles Loaded Parallel With a Leg (No. R799)

Abstract

This report presents the results of 11 compression tests performed on cold-Formed, inline galvanised, slender 50x50x2.5 DuraGal equal angles. The angles were tested between pinned ends and loaded axially with eccentric load which caused bending parallel with a leg at the ends. Tests were performed over a range of lengths to produce column strength curves. The sensitivity to load eccentricity was investigated by applying the load at the centroid, at a leg and at a point outside the section. Detailed measurements of material properties, residual stresses and geometric imperfections were conducted. The test data are compared with the design rules of the Australian Standards for ColdFormed (AS/NZS 4600-1996) and Hot-Rolled (AS 4100-1998) Steel Structures as well as the American Iron and Steel Institute (AISI-1997) Specification for the Design of Cold-formed Steel Structural Members, the American Society of Civil Engineers Standard (ASCE-1991) for the Design of Latticed Steel Transmission Structures and the American Institute of Steel Construction (AISC-1993) Specification for Load and Resistance Factor Design of Single-Angle Members. Recommendations on the application of these design rules to cold-formed angles are included in the paper. The test results show that the design rules of both Australian standards and the AISI and AISC specifications are conservative. The conservatism is most pronounced at short lengths. Improved design rules for AS/NZS 4600 and the AISI Specification are suggested. The design rules of the ASCE Standard are in fairly good agreement with the tests.