Numerical Studies on Innovative Prestressed Aluminium Alloy Profiles for Curtain Wall Systems

Aluminium curtain walls consist of thin extruded aluminium profiles, which are bearded by building structure, glass fixed on profiles, and subsidiary materials, such as EPDM (Ethylene propylene diene monomer) gaskets, membranes, brackets, silicone, etc. They can be arranged according to either stick (assembled on site) or unitized (assembled in shop) systems. These curtain walls are light, resistant to corrosion, and provide a nice appearance to the building facades. The main disadvantage of aluminium alloy systems is linked to the high material deformability, which makes challenging to absorb the building sway induced by wind and seismic forces respecting the standard provisions. To overcome this structural limitation, in the paper, a novel profile made of aluminium alloy and reinforced with tensioned steel wires to be used for curtain walls was conceived in the framework of a research contract between the Department of Structures for Engineering and Architecture (DIST) and the CMS Srl company. Firstly, numerical analyses were performed using the ABAQUS non-linear code on several extruded profiles to evaluate the system sensitivity to the number and location of wires. Finally, the performance of the reinforced profile was compared to that of the unreinforced aluminium alloy member, allowing us to find the optimal configuration of the aluminium alloy-steel mixed system to attain the maximum increase of stiffness and strength.