梁端腋板加强节点抗震性能试验研究

Experimental study on seismic behavior of haunched enhanced joints

针对钢框架梁端腋板加强节点,设计制作6个梁柱节点试件,进行低周往复加载拟静力试验,分析对称和非对称腋板加强式节点的破坏模式、承载力、延性、耗能、刚度及承载力退化等抗震性能,并与板式加强式和普通节点试件的抗震性能进行比较。试验研究表明:梁端腋板加强式节点试件在加载过程中表现出良好的塑性变形能力,能有效将塑性铰移至加强板以外位置,荷载-位移滞回曲线比较饱满,表现出良好的耗能能力和延性,加强板末端梁腹板设置的横向加劲肋可以减缓腋板端部变截面处的应力集中现象。非对称腋板加强式节点试件的正负向加载刚度表现出不对称性,随梁端塑性铰形成,等效刚度退化趋向稳定,普通节点试件等刚度退化曲线呈直线降低,非对称腋板加强式节点试件的承载力退化曲线波动较大。

For haunched enhanced joints in steel frame,six beam-column joint specimens were designed and tested under low-cycle reversed loading. Seismic performance such as failure mode,bearing capacity,ductility,energy dissipation,stiffness and bearing capacity degradation performance of symmetrical and asymmetric haunched enhanced joints were analyzed by comparing with that of plate enhanced joint specimen and ordinary joint specimen. The experimental results show that: haunched enhanced joint specimens exhibit good plastic deformation in the loading process which may help the plastic hinge move outside of the reinforced plate,the load-displacement hysteresis curve is full so that it exhibits good energy dissipation capacity and ductility,and setting horizontal stiffeners may help relieve stress concentration at variable cross-section at the end of the haunched plate. It is seen that the stiffness of asymmetric haunched enhanced joint appear to be asymmetric during positive and negative loading,the equivalent stiffness degradation tends to be stable with the forming of the plastic hinge at the end of the beam. The ordinary joint specimen stiffness degradation curve decreases linearly,while asymmetric haunched enhanced specimen capacity degradation curve fluctuates greatly.