By the hysteretic experiments and the finite element analysis of the proof-of-concept connections

the mechanical properties and energy dissipation capacity of the new steel beam-to-column connections are investigated. These connections are semi-rigid ones improved by adding threaded rods into the angle connections and can be designed to limit the structural damage only to the angles and threaded rods. It is found

by the comparative analysis of six connections tested with the same loading sequence

that the performance degradation of the connections may be resulted from the plastic damage

crack propagation of the angles and the buckling and fatigue crack of the rods. The rotation capacity and failure modes of the connections with threaded rods depend on the ability of anti-fatigue crack of the rods

and the better ductility the rods have

the better energy dissipation capacity the connections have. In addition

the hysteretic behavior and the deformation modes of the connections prior to the significant strength degradation or the fracture of the rods could be well simulated by the finite element method. Meanwhile

the stiffening effect from pre-stressing the angles

the plastic distribution of the angles and the degradation induced by the rod buckling were strongly verified by the FEA. Finally

the advantages and disadvantages of such new beam-to-column dissipative connections were analyzed

and the proposal for further connection improvement and in-depth study was made.