Seismic design of extended stiffened end-plate joints in the framework of Eurocodes

Bolted extended stiffened end-plate beam-to-column joints are widely used in seismic resistant steel frames. The flexural behaviour of this type of joints is crucial in order to guarantee an adequate seismic response. Eurocode 3 part 1-8 provides design rules and analytical models to predict the mechanical behaviour of the joints. Eurocode 8 provides additional design rules for seismic resistant joints, contradicting some requirements of Eurocode 3. In addition, in Eurocode 3 the influence of the rib stiffeners on the flexural response of this type of joints is not clearly accounted for. In this paper the criticisms of current versions of Eurocode 3 and Eurocode 8 are discussed and design criteria for seismic resistant extended stiffened end-plate beam-to-column joints are proposed. In addition, the results obtained from parametric finite element simulations are presented in order to support the discussion and to validate the design procedure.