预应力型钢混凝土梁-钢管混凝土柱节点抗震性能试验研究

通过5个试件的低周反复荷载试验，对预应力型钢混凝土(PSRC)梁-钢管混凝土(CFT)柱节点的受力过程、破坏形态、滞回曲线、骨架曲线、强度与变形特征值、延性、变形恢复能力、刚度退化、耗能能力等抗震性能进行了较为系统的研究，对预应力、轴压比、预应力筋穿越钢管壁的成孔方法（先成孔与后成孔）等因素对节点抗震性能的影响进行了分析。研究结果表明：PSRC梁-CFT柱节点发生了节点核心区剪切破坏；节点核心区水平剪力-剪切变形滞回曲线较丰满，但在大变形阶段有一定的捏拢效应；各试件节点核心区的极限剪切变形介于28.60×10^-3~60.90×10^-3 rad，剪切变形延性系数则介于4.72~6.69；各试件节点核心区的剪切刚度退化规律基本一致；施加预应力及后成孔方法对节点核心区受剪承载力有一定的有利影响，但施加预应力对节点核心区剪切变形能力及剪切变形延性不利；当轴压比n从0.2增至0.4时，节点核心区受剪承载力提高16.62%，而轴压比n从0.4增至0.6时，节点核心区受剪承载力仅提高1.09%。

Experimental research on seismic behavior of connection between prestressed steel reinforced concrete beam and concrete-filled steel tubular column

Based on tests of five specimens under low cyclic reversed loading, the failure pattern, hysteretic loops, skeleton curves, characteristic values of strength and deformation, ductility, deformation restoring capacity, rigidity degradation and energy dissipation capacity of connections between prestressed steel reinforced concrete (PSRC) beams and concrete-filled steel tubular (CFT) columns were systematically studied. The influences of prestressing force, axial compression ratio, drilling method including pre-drilling and post-drilling method and so forth on seismic performance of connections were studied. Experimental results show that the failure mode of connections between PSRC beams and CFT columns is shear failure in the panel zone. The hysteretic loops of the horizontal shear force versus shear deformation are plump, while pinching can be observed at large deformation stage. The ultimate shear deformations in the panel zone of the five specimens are between 28.60×10-3rad and 60.90×10-3rad, and the shear ductility coefficients in the panel zone of the five specimens are between 4.72 and 6.69. The degradation tendencies of shear stiffness of the five specimens are almost the same. Prestressing force and post-drilling methods have a little beneficial influence on the shear strength of connections, while prestressing force is unfavorable to the capacity of shear deformation and the ductility of shear deformation. The shear capacity of the specimens increases by 16.62% with the increase of axial compression ratio from 0.2 to 0.4. However, the shear capacity of the specimens increases only by 1.09% when the axial compression ratio increases from 0.4 to 0.6.