玻璃幕墙中铝合金立柱螺钉连接节点抗拉性能试验

Experiment on Tension Behavior of Aluminum Alloy Column with Screw Connections for Glass Curtain Wall

为研究玻璃幕墙中铝合金立柱螺钉连接节点的受力性能,通过一套自主设计的加载装置进行了20个连接件的单钉抗拉连接静力试验,分析了立柱和螺钉的3种典型破坏模式以及螺钉种类、螺杆直径、螺钉螺距和腐蚀条件等因素对连接件承载性能的影响,根据试验结果拟合出了铝合金立柱螺钉连接的极限抗拉承载力的计算公式。研究结果表明:铝合金立柱螺钉立柱连接节点的典型荷载-位移曲线上升段可分为弹性、强化、滑移3个阶段,可将强化阶段的强化极限点作为工程设计破坏阶段之用;在相近直径系列试件中,盘头螺钉的延性系数和极限刚度普遍大于自攻螺钉;螺钉类型、螺杆直径和腐蚀条件对节点的极限承载力和刚度影响最为显著,试件极限承载力随螺杆直径的增长而呈增大趋势,自攻螺钉试件的极限承载力大于盘头螺钉,而当自攻螺钉公称直径超过立柱型材局部厚度后,相对于盘头螺钉表现出承载力大幅下降的试验现象;通过回归分析得到的极限抗拉承载力计算公式与试验值比较,两者吻合良好。

In order to investigate the mechanical performance of aluminum alloy column with screw connections for glass curtain wall,twenty single-screw tension connection specimens were tested by a set of self-designed static loading device.Three typical failure modes of columns and screws were analyzed and the influences of the screw type,screw diameter,screw pitch and corrosion condition on the bearing capacity of connectors were analyzed.The computational formula for ultimate tensile capacity of such kind of connections was fitted according to the test results.The results show that ascending section of the typical load-displacement curve of connection specimens can be divided into three stages:elasticity and slip,and the elastic limit point of elasticity stage can be used as the failure stage of engineering design.The ductility coefficient and ultimate stiffness of pan-head screws are generally higher than self-tapping screws in the series of similar diameter specimens.Screw type,screw diameter and corrosion condition have the most significant influence on the ultimate bearing capacity and stiffness of connections.The ultimate bearing capacity of specimens increases with the increase of the screw diameter.The ultimate bearing capacity of self-tapping screws is greater than pan-head screws,and when the nominal diameter of self-tapping screws exceeds the local thickness of column,the bearing capacity of self-tapping screws decreases significantly compared with panhead screws.The calculation formula of the ultimate tensile strength formula obtained by regression analysis are in good agreement with the experimental values.