装配式人工消能塑性铰节点抗震性能试验研究

Experimental study on seismic performance of prefabricated joint based on artificial dissipative plastic hinge

为提高装配式钢筋混凝土(RC)框架结构的抗震性能,降低梁、柱构件震后损伤程度,提出了人工消能塑性铰(artificial dissipated plastic hinge, ADPH)节点,即在梁端通过预埋机械铰实现梁、柱构件铰接,同时安装附加钢板承载并耗能。试验中设计并制作了2个不同形式的ADPH节点和1个现浇RC节点,对3个节点进行了低周往复荷载试验,分析其破坏特征,并通过滞回曲线、骨架曲线、耗能能力、延性、刚度退化及应变等研究其抗震性能。结果表明:ADPH节点的破坏模式为附加耗能钢板中部的屈曲及轻微撕裂;相较现浇RC节点,ADPH节点的承载能力更高、延性更好、耗能能力增强,刚度退化较慢,抗震性能明显提高;而附加钢板过早屈曲易导致出现两侧附加钢板均受弯的状态,导致滑移段出现,降低耗能效率,应对附加钢板平面外变形加以控制;所建立的有限元模型可以较好地模拟ADPH节点的滞回行为。

To enhance the seismic resistance of precast reinforced concrete(RC) frame structures, and to decrease the damage of beams and columns after earthquakes, innovative joints at the beam end, termed artificial dissipative plastic hinge(ADPH), were proposed. ADPHs connected precast beams and columns though an embedded mechanical hinge and additional steel plates which were installed to carry the load and dissipate energy. The low-cycle reversed loading tests of two ADPH joints and one cast-in-situ RC joint were conducted and the failure modes of the joints were analyzed. In addition, the seismic performance of the joints were studied through the hysteretic curves, skeleton curves, energy dissipation, ductility stiffness degradation and strain. The results show that the failure mode of the ADPH joint is buckling and slight slit which occurrs at the middle part of the additional steel plates. The ADPH joint shows higher ultimate bearing capacity, better ductility, enhanced energy-dissipating capacity, and slower stiffness degradation, the seismic performance improves significantly compared with the cast-in-situ RC joint. It is also found that premature buckling may lead to bending of the steel plates on both sides, causing the appearance of slippage and reduction of efficiency of energy-dissipation, so the out-of-plane deformation of the steel plates should be controlled. The established finite element model can well simulate the hysteretic behavior of the proposed ADPH joint.