钢管混凝土柱-钢梁穿筋节点低周反复荷载下受力性能

Mechanical behavior of concrete-filled steel tube column-steel beam joints with penetration steel bars under low cyclic loading

对8个圆钢管混凝土柱-钢梁节点进行低周反复加载试验,其中6个节点设置了穿透钢筋,另外2个节点未设穿透钢筋,对节点的破坏位置和形态进行了分析,研究其抗弯承载力、延性和耗能能力.试验结果表明:节点穿筋将大部分弯矩直接传递给核心混凝土,降低了钢管的拉应力,显著提高了直接焊接钢梁节点的受力性能.穿筋节点具有较高的抗弯承载力、良好的延性和耗能能力,而未穿筋节点的抗弯承载力低,延性和耗能能力差.

8 Concrete-filled circular steel tube column-steel beam joints,6 joints with penetration steel bars and the other 2 joints without penetration steel bars,were tested under low cyclic loading.The failure position and shape of joints were researched.The flexural capacity,ductility and energy dissipation were analyzed.The experimental results indicate that penetration steel bars can transfer the most moment into core concrete,and decrease the tension stress in steel tube,thus obviously improve the mechanical behavior of joints on which steel beams are directly welded to the steel tube.The joints with penetration steel bars have high flexural capacity,excellent ductility and energy dissipation,and joints without penetration steel bars have low flexural capacity,poor ductility and energy dissipation.