Ricerc@Sapienza

Recently, the design of building skins is achieving a strategic role, to meet more and more complex requirements, especially towards the goal of Nearly Zero Energy Buildings (NZEB).
In this context, Double-Skin Façades (DSF) offer great potentialities and are becoming increasingly popular among architects and engineers. On the other hand, in tall buildings, excessive displacements and accelerations can cause serious human discomfort issues. To mitigate this type of problems, Tuned Mass Dampers (TMD) can be considered as the default solution. However, the installation of TMD implies the sacrifice of valuable space near the top floor and the addition of large masses to the building. To overcome such shortcomings, the idea to let the DSF mass oscillate in order to mitigate the vibrations of the building has been proposed in the literature. Some Authors showed that DSF can successfully work as a distributed TMD without addition of new mass nor demission of useful building space. However, the use of DSF to reduce structural vibrations is hindered by the fact that the effectiveness of the damping is correlated with large displacements of the external layer. Further advancement of this idea, is thus subordinated to the realization of façades capable to effectively act as TMD while keeping displacements of façade within acceptable levels.
This project aims to develop a connection that could help to fill this gap. This will be realized by the design and the numerical and experimental validation of a device with two-stage behavior composed by a low stiffness element supplemented by a second-stage motion limiter. One or both of the components could be realized by means of Shape Memory Alloys or innovative nanostructured materials, such as carbon nanotube/polymer nanocomposites. This could add further value to the project by establishing a link between DSF, initially conceived only to improve the energy performances, with the concepts of kinetic façades and intelligent skins.