Special joint systems for aluminium structures: experimental tests and numerical models

The wide choice of cross-sectional shapes obtainable by extrusion provides the possibility to individuate new joining solution for aluminium profiles. These joints, named “special” or “non-conventional” joints, are very competitive with respect to conventional solutions because of the possibility of rapid execution, optimization of parent material, treatments and machining reduction. For these reasons, the aluminium industry is very interested to enhance the knowledge about the structural behaviour of this joint typology. The work is focused on two different special joint systems: screw ports and bolt-channel joints. In particular, the first joint typology consists in a screw engaged in an open or closed slot of an extruded profile. The latter system consists in a track or channel section profile in which a bolt head, nuts or plates with threaded holes can be located. Special joints are used in several structural and non applications under low and moderate loads such as faà§ades, door and window fixtures. But, in the last years, other structural applications like staircases, floors, pedestrian bridge, industrial furniture and shelves have been developed involving special joints. Nevertheless, very little literature is available for this system and no specifications are provided by aluminium structures codes. The main objective of this work is to overcome the lack of information about the mechanical behaviour of special joints. In order to evaluate the structural behaviour of such joint, a wide experimental campaign has been carried out. In addition, on the basis of experimental results, non-linear finite element models have been developed and calibrated.