套筒式全螺栓装配式节点滞回性能及转动模型研究

Hysteresis performance and rotation modelling of sleeve-type fully-bolted prefabricated joints

  • 摘要: 为实现装配式RC框架快速施工与可靠连接,提出了一种套筒式全螺栓连接节点。预制构件端部采用钢套筒⁃混凝土组合形式进行加强,并预埋高强螺栓,通过钢盖板进行快速安装。针对不同连接盖板厚度,共设计4个节点试件,开展了水平滞回试验研究,得到破坏模式、荷载⁃位移滞回曲线、极限承载力、延性、耗能等抗震性能,并与现浇节点进行了对比分析。结果表明:该节点相较于现浇节点的极限荷载提高了43%,初始刚度提高了70%,延性增大近50%,等效黏滞阻尼系数提高2倍左右,表现出较好的抗震性能。应变分析发现:接缝处盖板出现“应力增大”情况,但对整体性能影响不明显。随着盖板厚度增加,套筒对端部混凝土产生的挤压作用变大,其连接刚度比为1.6较为合理。基于试验结果,建立了三折线弯矩⁃转角模型,计算结果与试验值吻合较好。

     

    Abstract: In order to achieve rapid construction and reliable connection of precast RC frames, a sleeve-type fully-bolted joint is proposed. The ends of the prefabricated components are reinforced with a steel sleeve-concrete combination. High-strength bolts are pre-built in the sleeve area, and the precast components are rapidly installed using a connection plate. A total of four test specimens were designed for different thicknesses of connecting cover plates. The horizontal hysteresis test study obtained the damage mode, load-displacement hysteresis curve, ultimate bearing capacity, ductility and energy dissipation capacity of this type of joint. The results show that the new joint has a 43% higher ultimate load, 70% higher initial stiffness and nearly 50% higher ductility than the cast-in-place joint, and the equivalent viscous damping coefficient is increased by about two times, which shows better seismic performance. Strain analysis reveals that the cover plate at the joints shows a “stress increase”, but the effect on the overall performance is not apparent. As the thickness of the connection plate increases, the squeezing effect of the sleeve on the concrete increases. Therefore, a connection stiffness ratio of 1.6 is more reasonable. Finally, based on the test results, a trifold moment-turning angle model is established, and the calculated results agree with the test values.

     

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