承载-双阶耗能装配式混凝土框架节点抗震性能试验研究OA北大核心

The prefabricated concrete frame joints,as crucial parts of prefabricated concrete structures,its seismic performance determined the integrity and post-earthquake repairability of prefabricated structures.To achieve seismic resilience and rapid assembly of the prefabricated structure,a fully prefabricated concrete beam-column-slab joint was proposed.A bearing-double-stage energy dissipation connector was embedded at the beam end to achieve yielding and energy dissipation in sequence of the bottom and mid-bottom flanges during fortification to rare earthquakes,and beam-slab connecting components were designed to eliminate the cracking damage of the prefabricated slab.Quasi-static tests were conducted on six prefabricated concrete frame joints and one cast-in-place concrete frame joint to study the influence of energy dissipation connector configuration,steel type,and the presence of prefabricated slab on the seismic performance of the joints.The hysteresis performance,stiffness and strength,energy dissipation capacity,and shear deformation of the joint core area were analyzed.The experimental results show that the damage of the innovative prefabricated joints is concentrated in the energy dissipation connectors,and the prefabricated concrete beams,columns,and slabs are in elastic states.While concrete crushing and reinforcement fracture are observed at the beam end of the cast-in-place joint.The proposed double-stage energy dissipation joints has higher first-stage post-yielding stiffness and better energy dissipation capacity than the single-stage energy dissipation joint.Besides,by replacing the damaged energy dissipation link,the repaired joint exhibits similar seismic performance as the previous joint,demonstrating great post-earthquake reparability.Finally,considering the incomplete combination of precast slab,precast beam,and energy dissipation link,a new method for calculating the ultimate flexural capacity of fabricated joints was proposed.The calculated results of the proposed formula are in good agreement with the experimental results.