M-N interaction in beam-to-column joints - Development of a design model

The component method is a nowadays widely recognized procedure for the evaluation of the design properties of structural joints. It is used as a reference method in the Eurocodes and the proposed rules in these codes are mainly devoted to the characterization of joints subjected to bending moments and shear forces. However, in some situations, these joints can be subjected to combined axial loads and bending mo-ments, for instance in frames subjected to an exceptional event leading to the loss of a column, situation where significant tying forces can developed in the structural beams above the lost column. In this paper, a design model, founded on the component method, aiming at predicting the behaviour of joints subjected to com-bined axial loads and bending moments is presented. In particular, it is illustrated how this model was vali-dated through comparisons to recent experimental tests performed on steel-concrete composite beam-to-column joints.