Experimental Analysis on the Cyclic Response of Beam to Column Joints: State-of-the-Art at Salerno University

Aiming to provide a contribution to the codification of design rules for dissipative joints to be applied to MRFs, in last five years, a comprehensive experimental and analytical work dealing with the cyclic behaviour of beam-to-column joints has been developed by the research group of the University of Salerno. In particular, the activity has regarded the study of both classical and innovative typologies characterized by the same initial stiffness and resistance but by different hysteretic behaviours due to the different source of energy dissipation supply imposed in the design process. In this paper, the main results of such a study, performed at the laboratory of materials and structures of the University of Salerno, are reported in order to provide an overview on the main mechanisms involved in the energy dissipation of partial-strength connections. A particular attention is given to the design issues by presenting the procedures aimed at providing to the joints adequate characteristics in terms of stiffness, resistance and ductility supply by hierarchically controlling the behaviour of the single joint components. Furthermore, the results of tested joints (classical and innovative) are compared in terms of hysteretic behaviour and energy dissipation supply in order to point out the advantages of the different connecting systems.