Maria Teresa Terracciano

Seismic Design Method for CFS Diagonal Strap-Braced Stud Walls: Experimental Validation

AbstractThe search for innovative methods to ensure high structural, technological, and environmental performance is an important issue in the development of new construction. Among the several available building systems, constructions involving the structural use of cold-formed steel (CFS) profiles represent an efficient and reliable solution. In an effort to characterize the seismic response of CFS structures and to support the spread of these systems, a theoretical and experimental research has been carried out. It focused on the all-steel-design solution, in which CFS diagonal strap-braced stud walls are the main lateral resisting system. In order to overcome the lack of information in the current European codes, a critical analysis has been carried out of the requirements for these systems in difference codes for hot-rolled X-braced steel frames (tension-only). On the basis of the design hypothesis outlined from this analysis, a case study has been developed with the aim to define an extended experim...

Shake Table Tests of Structures with CFS Strap-Braced Stud Walls

The unconventionality of the cold-formed steel (CFS) structures raised, in recent times, a lot of interest from many national and international companies resulting in the promotion of experimental activity with the main aim of investigating the seismic behaviour of these systems. In this perspective, a research project carried out at the University of Naples “Federico II” and funded by Lamieredil S.p.A. company started in the last years. The study included an extended experimental campaign, involving shake table tests on two three-storey prototypes in reduced scale (1:3). The investigated lateral load resisting systems were CFS strap-braced stud walls, designed as low dissipative seismic structures. The present paper illustrates case study, prototypes, test program and main shake table tests results.

Seismic Behaviour of Sheathed CFS Buildings: Shake-Table Testing and Numerical Modelling

In the past, the effort of the research was focused on the characterization and modelling of isolated CFS members or parts of building, but this cannot be enough for innovative structure, in which the sheathing panels interact with the steel framing providing the bracing effects against seismic actions. Therefore, in order to evaluate the seismic behaviour of CFS buildings sheathed with gypsum panels, a wide experimental campaign was conducted at University of Naples “Federico II” in the framework of European research project ELISSA (Energy efficient LIghtweight-Sustainable-SAfe steel construction). In particular, a two-storey building was tested on the shaking-table, considering different construction phases. In the first phase, the building included only structural elements and dynamic identification tests were carried out, whereas, in the second phase, the building was completed with all finishing components and it was tested for dynamic identification and under natural ground motions. In addition, a numerical model able to simulate the dynamic/earthquake response of the whole building, considering also the effect of finishing materials, was developed in OpenSees environment. The present paper describes the main results of shake-table testing and numerical modelling.

Seismic design and performance of low energy dissipative CFS strap-braced stud walls

The seismic performance of cold formed steel (CFS) strap-braced stud walls was evaluated in previous tests by monotonic and cyclic tests on full-scale specimens designed according to the elastic approach. Even if an elastic seismic design approach was followed, based on the experimental results, these walls exhibited a low but not negligible energy dissipative behaviour. Therefore, the current paper is focused on the seismic performance evaluation of low energy dissipative CFS strap-braced stud walls. In particular, starting from the critical analysis of current seismic codes, the paper presents a procedure for the prediction of strength and stiffness according to design rules provided by EN 1993-1-3, which was used to design case studies. Then, a test-based evaluation of behaviour was performed and values of the behaviour factor from 1.52 to 3.61 were obtained for low energy dissipative CFS strap-braced structures.