• Progetto di un'abitazione unifamiliare - Normogrammi

  • Test sperimentali

HOUSING

The growing demand for pre-engineered, sustainable and high performance houses increases the interest for cold-formed steel housing (CFS). CFS housing provides benefits coming from dry constructions (guaranteed quality of product, short execution time, and lower costs) and typical benefits of cold-formed steel systems (lightness, high structural performance and good behaviour under seismic actions). In addition, the use of recyclable materials, the flexibility of systems and the possible reuse of elements assure a low environmental impact. Main aims of this research is the study of the seismic behaviour of CFS structures and the proposal of design procedure for CFS housing in seismic area, that can be readily used by designers. The study has benn focused on the seismic behaviour of CFS shear walls sheathed with oriented strand board and/or gypsum board panels. The first part of the experimental phase has been carried out on two, nominally identical, prototypes, which were designed in such a way to contain all the structural elements and components used for this type of structure. The specimens have been tested under monotonic and cyclic loading conditions. Moreover, all the components have been designed according to capacity design criteria, imposing collapse in the sheathing connections of the shear walls. In a second phase, a wide experimental campaign aiming at characterizing the shear behaviour of different sheathings and sheathing-to-CFS profiles connections has been carried out. A numerical study has been developed in parallel to the experimental ones and it has been developed in the following phases: (1) definition and calibration of an ad hoc mathematical model of the hysteresis response of sheathed stud walls, that takes into account the strong nonlinearity of the response for small lateral displacements and the strong pinching of hysteresis loops; (2) selection of the seismic inputs; (3) numerical analysis; (4)  definition of loading protocol for the cyclic tests; (5) proposal of a analytical-numerical model for the evaluation of force-displacement curve of the shear walls. The theoretical and experimental results have been accounted for the proposal of a seismic design procedure, that allows the shear wall components to be defined in few steps. The procedure is based on the recognized assumption that the best performance of a CFS shear wall is achieved when the sheathing-to-stud fasteners failure is reached. All the results are available on several international papers.

RESEARCH PROJECT

  • “Abitazioni per la gestione dell’emergenza” RELUIS-DPC LINE 10 (Definizione e sviluppo di archivi di dati per la valutazione del rischio, la pianificazione e la gestione dell’emergenza Sviluppo di Approcci Innovativi per il Progetto di Strutture in Acciaio e Composte Acciaio-Calcestruzzo), 2005-2008.
  • “Metodologie e criteri di progetto per l’housing in cold-formed in zona sismica”  Research Project of Natinal Interest (PRIN): “Strutture metalliche innovative per la protezione sismica di edifici nuovi ed esistenti: criteri e metodologie di progetto”, 2003-2005.
  • “Studio teorico-sperimentale sulla possibilità di impiego dei profili di acciaio formati a freddo in zona sismica ” Research Project of Natinal Interest (PRIN): “Strutture di acciaio innovative per la protezione sismica degli edifici”, 2001-2003.

RESEARCH GROUP