TESTS OF COLD-FORMED FERRITIC STAINLESS STEEL PERFORATED BEAMS OF RECTANGULAR HOLLOW SECTIONS

An experimental investigation on cold-formed ferritic stainless steel perforated beams of rectangular hollow sections is presented in this paper. The test specimens were cold-formed tubular rectangular hollow sections with nominal dimension of 60x40x4, 80x60x4, 100x40x2 and 120x80x3. Two circular holes were drilled at mid-height of both webs for each section. The centers of the circular holes were located at the mid-length of the beam. Diameters of the circular holes equals to 0% (no hole), 20%, 50% and 80% of flat portion of webs. A total of 20 four-point bending tests was performed. The flexural capacity and the corresponding curvature as well as the failure modes of the specimens were obtained. The test results were compared with design strengths predicted by direct strength method in the North American Specification for carbon steel, which includes the strength reduction by the holes. It should be noted that the existing design specifications do not provide design rules for ferritic stainless steel perforated beams.