Static Experimental Analysis and Optimization of Innovative Pre-Engineered Tubular Section Beam-Column Connections in Cold-Form Steel Frames

The lack of connection configuration forms is one of the main bottlenecks, restricting the application of pre-engineered lightweight cold-form steel structures with tubular steel section. In this study, two innovative pre-engineered tubular steel section beam-column connections (namely JD1 and JD2) were proposed and designed in terms of the configuration and geometry. The developed finite element modeling of the proposed connections was implemented, and the refined finite element model was confirmed by comparison to static loading tests of two types of connection joints, JD1 and JD2. The mechanical properties and the geometry effect of the components of the JD1 and JD2 were systematically analyzed to determine the optimized configuration. The bearing capacity and stiffness of connection JD2 with upper and lower ribbed angle steels increased by 45.2% and 71.2%, respectively, compared to those of connection JD1 with lateral angle steels. The bearing capacity of the newly designed pre-engineered connection is close to that of the traditional welded joint. Nevertheless, the initial stiffness of the welded joint is obviously larger than that of the connections JD2 and JD1. The new pre-engineered fabricated connection was systematically compared with the traditional welded connection in terms of the construction convenience, economy, and mechanical properties. The connection form can be comprehensively considered based on the mechanical performance and construction requirements in construction applications.