梁贯通式圆钢管混凝土柱-混凝土梁边节点的抗震性能

Seismic Behavior of Exterior Through- Beam Joint Between Concrete-Filled Steel Tubular Columns and Reinforced Concrete Beams

通过4个梁贯通式圆钢管混凝土柱-混凝土梁边节点试件的低周反复荷载试验,研究了此类型边节点的抗震性能.试验结果表明:随着环梁与框架梁配筋率比值、环梁宽度与圆柱直径比值的减小,试件破坏区域由框架梁根部向环梁转移,并出现框架梁根部塑性铰破坏、框架梁与环梁交界处破坏、环梁区破坏3种不同的破坏形式;梁贯通式节点的梁端内力能够可靠传递至节点核心区,环梁节点可与框架梁、钢管混凝土柱协调工作;按"强节点"设计试件塑性铰出现在框架梁根部,滞回曲线饱满,延性系数较大,环线刚度曲线呈下凹型趋于收敛,耗能能力也较大,体现出良好的抗震性能;通过合理设计的梁贯通式圆钢管混凝土柱-混凝土梁边节点受力安全可靠,可实现"强柱弱梁,节点更强"的抗震设计原则.

The low-cycle reversed loading experiments of four specimens were conducted to investigate the seismic behavior of the exterior through-beam joint between concrete-filled steel tubular （ CFST ） columns and reinforced concrete beams.Experimental results show that （1） as the relative reinforcement ratio （the reinforcement ratio of ring beam /the reinforcement ratio of frame beam ） and the relative radio width ratio （ the width of ring beam /the diameter of steel tube ） decrease , the plastic hinge transfers from the frame beam to the ring beam , and three failure modes occur , which includes the failure at the frame beam root , the failure at the connection of the frame beam and the ring beam and the failure in the ring beam; （ 2 ） the internal force at the roots of the beams can be reliably transmitted to the joint , and the joint can work coordinately with the frame beam and the CFST column;and （ 3 ） for the specimens designed on the basis of the principle of “Strong Joint”, the plastic hinge appears at the frame beam root with plump hysteretic curves , relatively large ductility coefficient , concave and convergent stiffness curves and excellent energy dissipation ability , which means that the seismic behavior is good .Therefore, the exte-rior through-beam joint obtained through reasonable design is safe and reliable under stress , and it can realize the anti-seismic design principle of “Strong Column with Weak Beam is , Stronger in Joints”.