Seismic behaviour of diagonal strap braced CFS structures

The main scope of this dissertation has been to give a contribution to the evaluation of seismic performance of CFS structures and in particular of diagonal strap braced walls. To this end, two main objectives are pursued in this work: the study of the seismic behaviour of diagonal strap braced walls in terms of global response and the study of local behaviour of connections to understand their influence on the global seismic behaviour of walls. In the context of ReLUIS-DPC project, a wide experimental program was planned and carried out. It consists of full-scale experimental tests on walls to investigate the global behaviour and small-scale experimental tests on materials, simple mechanical joints and connections to investigate the influence of the local behaviour on the global seismic behaviour. The experimental tests have been performed at the Dist Laboratory (Department of Structures for Engineering and Architecture, Naples), of the University of Naples Federico II. The obtained results demonstrate a satisfactory experimental response in terms of stiffness, strength and deformation capacity, largely confirming the theoretical predictions. Since the final scope of the whole study, and in particular of the experimental campaign, is to provide appropriate design criteria for diagonal strap braced CFS structures to be introduced in Italian seismic code, considerations about design criteria were presented, on the basis of the design assumptions and the experimental test results, in comparison with the prescriptions of national and international seismic codes. The attention is focused on the behaviour factor, the diagonal brace verifications and the overstrength of fragile elements.