Comparison of Design Methods for Tensile Capacity of Screw Connections in Cold-formed Steel Structures

Based on the relevant research literature and the existing 342 sets of self-drilling screw tensile test results, the research status of the pull-out behavior and pull-over behavior of self-drilling screw connection in cold-formed steel structure were summarized. The calculation accuracy and applicability of self-drilling screw design methods in Technical Code of Cold-formed Thin-walled Steel Structures(GB 50018-2002), Technical Code of Cold-formed Steel Structures (Draft for Comments), American code (AISI S136-16), Australian code (AS/NZS 4600:2018), British code (BS 5950-5-1998) and European code (BS EN 1993-1-3:2006) were compared and analyzed in this paper. Results show that design method in Technical Code of Cold-formed Steel Structures (Draft for Comments) has highest accuracy and applicability. For 550 grade steel plate with thickness lower, a reduction factor of 0.8 on the tensile capacity is needed. For medium and low strength steel plate with thickness more than 2 mm, design value by Technical Code of Cold-formed Steel Structures (Draft for Comments) is uneconomical. In addition, it is suggested that the ratio of nominal diameter of screw to plate thickness should not exceed 8 to ensure that the connection performance of self-drilling screw and steel plate can be better exerted when the maximum pull-out capacity of screw joint is reached.