预制混凝土管组合柱-钢梁连接节点抗震性能试验研究

Experimental study on seismic behavior of concrete-filled precast concrete tube column to steel beam connections

为研究预制混凝土管组合柱-钢梁连接节点的抗震性能,以轴压比、钢套箍延伸高度、芯部混凝土强度以及钢套箍厚度为主要参数,进行了6个1/2缩尺节点的拟静力试验。研究了各节点的破坏形态、滞回特性、承载能力、耗能能力以及节点域受剪性能。试验结果表明:各节点主要破坏模式均为节点域剪切破坏;滞回曲线呈典型弓形,耗能能力较好;芯部混凝土强度和钢套箍厚度是影响节点抗震性能的关键参数,对承载能力和耗能性能影响较大;破坏时节点域极限剪切变形介于0.0482~0.100 rad之间;节点域受剪承载力降低系数介于0.86~1.00之间,承载力退化性能稳定。建立了预制混凝土管组合柱-钢梁连接节点受剪承载力计算式,计算值与试验值吻合较好且偏于安全。

To study the seismic behavior of concrete-filled precast concrete tube column to steel beam connections,an experiment of six half-scale beam-column joint specimens was conducted under cyclic loads with different axial load levels,the heights of extended joint steel tube,the filled concrete strengths,and the thicknesses of joint steel tube.The failure modes,hysteresis behavior,bearing capacity,energy dissipation and joint shear behavior of each specimen were investigated.The test results indicate that the primary failure mode for each specimen is shear failure in joint zone.The hysteresis curves present a typical bow shape with sound energy dissipation capacity.The filled concrete strength and the thickness of joint steel tube are the critical parameters that affect the seismic behavior of joints,and they have a noticeable effect on the bearing capacity and energy dissipation capacity.The ultimate shear distortion in joint zone for each specimen range from 0.0482 to 0.100.The shear strength degradation coefficients for the specimens are between 0.86 and 1.00,exhibiting stable strength degradation behavior.The calculation formula of the shear bearing capacity of the joint are proposed.It shows that the calculation results agree well and are conservative as compared to the test results.