Performance evaluation of cold‐formed steel spot weld connections

[Spot welding is a fast and productive technology widely used in industry to join various cold‐formed steel (CFS) elements. Depending on the type of analysis and model complexity, various definitions of spot welds in finite element (FE) models can be applied. In structures with a large number of spot welds, simple models that use a reduced number of elements should be used because detailed models have too many degrees of freedom. This study deals with the investigation of point‐based fasteners in FE analysis for spot weld connections in CFS structures. The paper summarises the experimentally determined results of the spot‐welded connections in shear for eight groups of spot‐welded connections made of sheet thicknesses 0.8, 1.0, 1.5, 2.5 and 3.0 mm. The shear performance tests show different failure modes: full button pull‐out failure mode and interfacial fracture. Based on the test results, the FE models for spot‐welded connections were calibrated. The FE models for shear connections were created in ABAQUS using the simplified method based on point‐based fasteners and explicit dynamic analysis. Experimentally and numerically obtained results were compared with analytically calculated characteristic resistances of spot welds according to European standards.