Effect of SMA bar-friction damper series device on hysteretic performance of steel semi-rigid and hinged joints

The extensive application of steel material in Chinese archaized buildings not only represents the unique exterior appearance of traditional architecture but also effectively addresses issues such as the susceptibility to decay and deformation in wooden structures. However, conventional rigid beam-column welded connections in steel archaized buildings are prone to premature rupture under seismic events. To further enhance the energy dissipation capacity and post-earthquake repairability of beam-column joints in steel archaized buildings, this paper proposes a self-centering energy dissipation device composed of shape memory alloy (SMA) bars and friction dampers connected in series. Four full-scale joint specimens with different joint stiffnesses were designed and subjected to low-cycle repeated loading tests. The results indicated that the combination of semi rigid beam-column joints and self-centering energy dissipation devices using shear-type friction dampers exhibit stronger energy dissipation and load-bearing capacities with minimal residual deformation compared to other configurations. Based on experimental results, a three-dimensional numerical model was established using ABAQUS finite element software to investigate the effects of beam end-plate thickness and the length of weak zone in the extended limb length in angle steels on the mechanical performance, energy dissipation capacity, residual deformation, and self-centering performance of beam-column joints in steel archaized buildings equipped with SMA bar-friction damper series devices. Finally, design recommendations were provided for the end-plate of the beam and the replaceable angle steel at the beam-column joints in steel archaized buildings.