Experimental characterization of quick mechanical connecting systems for cold-formed steel structures

Among the several available building systems, constructions involving cold-formed steel profiles represent an efficient and reliable solution. These systems are very suitable to be used in pre-fabricated modular constructions, thanks to their lightness and possibility to automate the building process. In these systems, connections are usually made with self-tapping screws and play a key role both in fabrication, for reducing assembling times of modular units, and in structural behaviour, particularly for sheathing-braced solutions. In a framework of the European project ELISSA (Energy Efficient LIghtweight-Sustainable-SAfe-Steel Construction), which was devoted to the development and demonstration of cold-formed steel modular systems, an experimental campaign on quick connecting systems alternative to screws was carried out. This article shows the results of this experimental activity, consisting of monotonic and cyclic shear tests on connection systems. In particular, the tested specimens are clinching for steel-to-steel connections, whereas the fasteners used for panel-to-steel connections of walls and floors are ballistic nails. Tests results provided important information on the shear response of the connections with particular reference to the values of strength and stiffness, which are the main parameters for developing the seismic design of sheathed shear walls.