Structural behaviour of Cold‐Formed Steel back‐to‐back welded sections subjected to longitudinal shear

The current study focuses on understanding the behaviour of flare v‐groove welds on back‐to‐back connected Cold‐Formed Steel welded sections (G300) subjected to longitudinal shear. A novel welding technique called Cold Metal Transfer (CMT) welding was used for fabrication with copper‐coated steel welding wire as a filler metal (ER70S‐6). This mode of welding has the advantage of controlled material deposition compared to the spray or globular mode of welding. Lap shear tests were carried out on unlipped channels including thickness of the weld, and length of the weld. The weld geometry was observed under an optical microscope after polishing and chemical etching of the weld cross‐section, as American Iron and Steel Institute (AISI) design standard provides no specification on thickness of flare v‐groove welds for CMT welding process. In general, the lap shear specimens failed in plate tearing failure mode and brittle fracture of weld at the weld contours. Additionally, the appropriateness of AISI's shear design strength equations for flare v‐groove welds was verified and preliminary design guidelines are provided addressing the lacunae in AISI design standard.