In this study, an innovative fabricated angle bracket connection for joining cold-formed steel structures is presented and investigated. The innovation lies in the especially designed and manufactured angle bracket and in the method of connecting the angle bracket for the C-profile using clinch pressing. This novel angle bracket can be used to connect cold-formed steel elements such as beam trusses at the ends of the chords or for anchoring the column base. Five specimens were fabricated and experimentally tested under monotonic tensile loading until failure. A specific tool was developed to properly hold C-profiles. Three displacement measurement procedures were performed, and the appropriate method was used to analyse the test results. The main failure mechanism of the angle bracket connection determined by the tests was pull-through of the M12 bolt, whose resistance is compared with the calculated values according to the AISI S100-16 and EN 1993-1-3 standards. There was no bearing failure in the innovative connection between the C-profile and the angle bracket, which indicates an increase in the bearing capacity of the connection.

U radu je predstavljeno istraživanje u okviru znanstvenog projekta ZIP UNIRI„Istraživanje ponašanja komponenti kompozitnog panela s integriranom čeličnomjezgrom“. Cilj znanstvenog projekta je pružiti bolje razumijevanje o ponašanjukomponenti inovativnog konstruktivnog panelnog sustava kako bi se istražiopotencijal njegove primjene u građevinarstvu.

This study presents an innovative design for a cold-formed steel polyurethane (CFS-PU) composite wall panel, combining a cold-formed steel frame, a polyurethane foam infill, and a gypsum fibreboard sheathing. The foam filling process, in which the foam is injected under pressure, ensures uniform distribution, bonding, and interaction of all panel components. The aim of the study is to evaluate the behaviour of the CFS-PU composite panels and the influence of the PU foam and sheathing on the performance of the CFS frame structure. For this purpose, a comprehensive test programme was conducted with nine full-scale specimens, including four CFS-F specimens without infill and sheathing and five CFS-PU specimens with infill and sheathing on both sides. The study examined various aspects of the specimens, including failure modes, stability, stiffness, load-bearing capacity, and ductility index. By analysing these parameters, valuable insights were gained into the performance characteristics of the composite wall panels. The load-bearing capacity of the CFS-PU test specimens was improved by 2.34 times and the stiffness by 1.47 times compared to the CFS-F test specimens. The positive results highlight the potential of foam and sheathing in improving the axial compression performance of CFS walls.

This paper presents an experimental and numerical investigation of the tensile and compressive behaviour of a novel U-connector in the cold-formed steel (CFS) truss-to-column connection. Tensile tests were performed on 12 specimens representing the tension chords of the trusses in the connection. The results were used to validate a finite element model. The validated model was then subjected to both compressive and tensile loads, which revealed low stiffness in both the compressive and tensile components of the proposed connection. An optimisation of the geometry by using one long nut instead of two nuts was carried out to improve the behaviour and stiffness of the connection. The optimised results were compared with both experimental and numerical data, and conclusions were drawn regarding the effectiveness of the components in the proposed connection. The use of long-nut optimisation in the tension and compression components of the proposed connection shows a significant increase in load-bearing capacity, which makes it very promising for future applications in CFS truss-to-column connections. However, further validation through experimental testing is required to confirm the effectiveness and reliability of the connection in full-scale structures.