Behaviour of pin partial strenght beam-to-column connections with double channel cold-formed steel sections

Abstract

The application of cold-formed steel in light steel framing design can become a popular choice of Industrialized Building System (IBS), by extending the steelwork design into residential housing. However there is a lack of in-depth study on the joints behaviour for primary structures, particularly the beam-to-column connection. The objectives of this research are to develop the design procedures of bolted beamto- column connections for double channel cold-formed steel sections, to study the pin and partial strength behaviour of the developed connections based on their strength and stiffness performance, and to validate the performance of the proposed connection configurations by comparing the analytical calculation to experimental results. Analytical study was carried out to develop design procedures for five types of joint methods, namely double angle web-cleats (J1-WC), top-seat flange-cleats (J2-FC), combined flange-web-cleats (J3-FWC), gusset plates (J4-HG) and combined gusset plate flange-cleats (J5-HGFC) to form bolted connections to accommodate members in practical orientations. A series of full scale experimental investigation comprised of twenty-four isolated joint tests and twelve subassemblage frame tests have been carried out to understand the connections’ strength and stiffness behaviour. The experimental results showed good agreement compared to theoretical prediction. From the experimental and analytical results, J1-WC, J2- FC and J3-FWC connections were classified as pin joints, with the strength less than 25% of beam capacity; while J4-HG and J5-HGFC connections were classified as partial strength joints with moment resistance of joint in the range of 46% to 96% to the moment resistance of the connected beam. It was concluded that among the five types of proposed connections, J1-WC, J2-FC and J3-FWC connections were designed as pin joint, J4-HG and J5-HGFC connections were validated to be used as partial strength joints.