Seismic pre-qualification tests of EC8-compliant external extended stiffened end-plate beam-to-column joints

•Tests to prequalify EC8-compliant extended stiffened end-plate joints are presented.•Design procedure is proposed and verified against tests and finite element simulations.•Two alternative dissipation mechanisms are promoted, i.e., full and equal strength joints.•Tests showed plastic deformations solely in the connected beam for full strength joints.•Tests showed plastic deformations in the beam and the connection for equal strength joints.