Analytical investigation of a novel joist‐to‐stud web connection in light steel framed buildings

In typical light steel framed (LSF) buildings, floor joists are connected to studs through web connections assuming pinned behaviour. This often results in deeper joist sections, as the design is primarily governed by mid-span deflections. Consequently, the full load-bearing capacity of cold-formed steel (CFS) elements is underutilized, leading to heavier structures and increased environmental impact. This paper investigates the behaviour of a novel semi-rigid joist-to-stud connection, where the joist and stud webs are screwed together. The semi-rigid nature of this connection allows for the development of rotational stiffness and bending resistance, enabling the use of smaller joist sections and more efficient utilisation of structural capacity. To this end, detailed experimentally validated Finite Element (FE) models are developed in ABAQUS software to assess the influence of key design parameters, including connecting element sizes, screw arrangements, construction methods and gravity loads, on the structural performance of joist-to-stud connections. The performance of the connections is compared in terms of initial stiffness and flexural strength. Depending on the screw configurations and the section sizes, two main failure mechanisms are anticipated: (i) shear failure in the screwed connection; (ii) local buckling of the stud or joist flanges near the connection zone. The results indicate that implementing a semi-rigid connection led to an average 25% reduction in the steel weight of the structure of six storey case study buildings compared to its conventionally designed counterpart with simple connections.