拼接缝对装配式RC结构节点抗震性能的影响

Effect of splicing joints on seismic performance of prefabricated RC structural nodes

为研究拼接缝对装配式RC结构节点抗震性能的影响,提高结构抗震能力,设计并制作了6个节点试件,通过低周反复荷载试验测出节点的破坏形态和滞回曲线。在此基础上用ABAQUS有限元软件,分析拼接缝对不同类型节点抗震性能的影响和拼接缝在节点梁上的最优位置。结果表明:设置拼接缝对边节点的抗震性能影响大于中节点,拼接缝在梁上的位置变化对中节点的抗震性能影响大于边节点;相同工况下中节点峰值承载力比边节点高30%,破坏位置的位移比边节点大约32%,耗能能力显著强于边节点;节点梁上的拼接缝位置变化对节点承载力、刚度退化、延性、耗能能力存在影响;拼接缝在梁上的最优位置为拼接缝距核心区约2/9梁跨长,最不利位置为距核心区约1/3梁跨长,在实际工程中应尽量合理设置拼接缝位置;装配节点梁上的拼接缝随着距离节点核心区长度的增加,节点主裂缝的位置逐步由核心区梁端变成拼接缝界面处,破坏方式逐步由梁端弯曲破坏变为梁端剪切破坏。

In order to study the effect of splicing joints on the seismic performance of prefabricated RC structural nodes,and to improve the seismic capacity of the structure,six node specimens were designed and produced,and the failure forms and hysteresis curves of the nodes were measured through low-cycle repeated load tests.On the basis,ABAQUS finite element software was used to analyze the influence of splicing joints on the seismic performance of different types of nodes and the optimal position of the splicing joints on the joint beams.The results show that the effect of splicing joints on the seismic performance of edge nodes is greater than that of mid-node,and the position changes of splicing joints on the beam have greater impact on the seismic performance of mid-node than that of edge node.Under the same working conditions,the peak bearing capacity of the mid-node is 30%higher than that of the edge node,and the displacement of the damage position is about 32%higher than that of the edge node,and the energy consumption capacity is significantly stronger than that of the edge node.The position change of the splicing joint on the joint beam has an impact on the node bearing capacity,stiffness degradation,ductility,and energy consumption capacity.The optimal position of the splicing joint on the beam is that the splicing joint is about 2/9 of the beam span from the core area,and the most unfavorable position is about 1/3 of the beam span from the core area.In the actual project,the position of the splicing joint should be set reasonably as far as possible.As the length of the splicing joint on the assembled node beam from the core area of the node increases,the position of the main crack of the node gradually changes from the beam end of the core area to the interface of the splicing joint.The failure mode gradually changes from bending failure at the beam end to shear failure at the beam end.