Investigation of conical roof beam under vertical loads: Experimental and parametric studies

This study presents experimental and numerical analyses to investigate the bending behavior of cold-formed steel (CFS) conical roof beams under vertical loads. The effects of radial beam orientation (face-to-face and face-to-back) and the spacing between circular beams (4500 mm, 1800 mm, 900 mm) on moment capacity, buckling modes, and deformation behavior were examined. Six single-span beam systems were tested, and it was observed that decreasing the spacing between circular beams increased the moment capacity and altered the buckling modes. The face-to-back orientation of radial beams reduced lateral displacement and rotation angles. Experimental results were validated using finite element analysis, and parametric studies were conducted. The parametric analyses revealed that decreasing the height-to-thickness (h/t) ratio of radial beams increased the moment capacity, while the thickness of circular beams had a limited effect. The results were compared with AISI S100–16 standards and an additional method to estimate local and distortional buckling capacities more accurately within the existing DSM approach.