STRENGTH OF CONNECTIONS BETWEEN SHS COLUMNS AND THROUGH PLATES

The use of Square-Hollow-Section (SHS) members as columns of moment-resisting frames is a very interesting solution thanks to several benefits they can provide: (i) high values of the radius of gyration; (ii) absence of a weak axis; (iii) reduction of the paintings, fire and corrosion protection costs thanks to the low surface area, compared to the double-tee profiles; (iv) lower drag coefficients affecting wind forces; (v) higher aesthetical aspect. However, especially in Europe and the USA, the use of SHS columns is limited by the complexity related to the realisation of beam-to-column connections. Nevertheless, the recent use in civil engineering of Laser Cutting Technology (LCT) has offered the opportunity to manufacture welded connections by properly cutting the tubular profile with the imprint of the cross-section shape of the double-tee member. Such a solution is an improved alternative to the joint with the I-beam welded to the external surface of the hollow profile since higher flexural strength and stiffness can be provided. Considering the importance of such a topic, this connection is currently being studied at the University of Salerno within the framework of the component method approach. In this view, the research activity discussed in this paper studies the monotonic behaviour experienced by welded connections between SHS tubes and through-all plates. In fact, this component is representative of the actions applied on the tube by each of the beam flanges of a double-tee profile. In particular, this nodal component has been studied thanks to numerical simulations carried out in IDEAStatica, and theoretical approaches derived by applying the yield-line and yield-field methods, leading to analytical design formulations.