Investigation on seismic performance of friction energy-dissipating prefabricated concrete frame joints

To enhance the seismic performance, assembly efficiency, and post-earthquake repairability of precast structures, this study proposes a novel friction energy-dissipating precast concrete beam-column joint. The design features pre-embedded steel connections in columns and beams, facilitating energy dissipation via controlled relative slip between the flange cover plates and the embedded steel structures. Experimental investigations were conducted on four specimens, including one cast-in-place concrete joint and three friction energy-dissipating precast concrete joints. Parameters such as energy dissipation capacity, stiffness degradation, and post-earthquake repairability were analyzed based on recorded failure modes and hysteretic curves. The results indicate the reliability of the proposed joint. Compared to cast-in-place concrete joints, the novel friction energy-dissipating precast concrete joint demonstrates significantly improved ductility, a 23 % increase in energy dissipation capacity, and enhanced overall seismic performance. Furthermore, increasing the thickness of the flange cover plate improves joint ductility with minimal impact on bearing capacity. The incorporation of semi-rigid connections in the joint core area effectively delays damage to the main reinforced concrete portion. The detailed finite element model has enough accuracy in predicting the behavior of friction energy-dissipating joints and finite element simulation results sufficiently show that the energy dissipation at the joints is in the form of frictional energy dissipation. In conclusion, the novel friction energy-dissipating precast concrete joint presents a promising avenue for further improvement and application in precast concrete frame structures, addressing the demand for enhanced seismic resilience, efficient assembly, and post-earthquake repairability.