Compression Tests of Welded Channel Section Columns

A test program is described investigating the compressive strength of channel section columns of slender cross section. The program consisted of different geometries of cross section, each fabricated by welding from high-strength steel. Specimens were tested both concentrically and eccentrically between pinned ends, and for each section geometry, fixed-ended stub column tests were also performed. Additional tests were performed to determine the local buckling load of the sections under uniform compression. The different behavior of the columns that were pinned or fixed at the ends is described, including the effect of the change in the position of the internal force after local buckling of the sections. Data on the test sections described in the paper include models of the measured residual stress distributions resulting from fabrication, the local geometric imperfection components measured in the plates after fabrication, and the measured imperfections in the shape of the overall flexural buckling mode. The test strengths are compared with predictions of the AISC Load and Resistance Factor Design Specification, the draft Limit State Australian Standard, the British Standard BS5950, Part I, and the Eurocode3 Specification for the design of steel structures. Conclusions regarding the accuracy of different specifications and standards are given in the paper.