装配式套筒连接CFST柱-RC梁节点抗震性能

Seismic behavior of precast sleeve-connected CFST column to RC beam connection

结合装配式节点和钢管混凝土（CFST）柱-钢筋混凝土（RC）梁节点各自优点,提出新型装配式套筒连接CFST柱-RC梁节点.为探讨该类节点抗震性能,对8个足尺劲性装配式套筒连接CFST柱-RC梁节点进行了低周往复荷载试验研究,考察了柱轴压比、梁柱连接角度（45°、90°）、梁柱位置（中间节点、边节点）对该类节点抗震性能的影响,对节点破坏形态、失效机制、滞回性能、骨架曲线、位移延性和耗能能力进行分析.采用ABAQUS程序建立节点的精细有限元模型,验证了其正确性.研究表明：该类节点具有＂强钢管混凝土柱-弱钢筋混凝土梁＂、＂强节点-弱构件＂的理想失效机制和较高承载力,试件加载至3~4.5倍屈服位移时因套筒位置附近纵筋拉断而破坏;节点耗能能力较强,变形能力较好,45°节点的平均位移延性系数〉3,90°节点的平均位移延性系数〉4.

Combining the advantages of precast connections and concrete filled steel tubular （CFST） column to reinforced concrete （RC） beam connections, a stiffened precast sleeve-connected CFST column to RC beam connection was proposed. Considering axial compression ratio, connected angle and location of the connection, pseudo-static experiments were conducted to investigate the earthquake resistance of the connections, whose failure mode, failure mechanism, hysterical behavior, envelop curve, ductility and energy-dissipating capacity were analyzed. Fine finite element models were built and verified by ABAQUS. The results show that： this type of connection could exhibit ＂ strong CFST column-weak RC beam＂ and ＂ strong connection-weak member＂ failure mechanisms and have excellent load carrying capacity, specimens fail due to the fracture of longitudinal reinforcement up until vertical displacement of beam-end reaches to 3-4.5 times of yield displacement; this type of connection also has excellent energy dissipating capacity and ductility, ductility coefficients of the connections with a 45 degree connected angle and 90 degree connected angle are respectively greater than 3 and 4.