冷弯薄壁型钢墙体-楼板节点抗震性能试验研究

Experimental research on seismic behavior of thin cold-formed steel wall–floor connections

开展考虑不同构造、轴压比、墙架柱截面类型及覆板蒙皮作用的7个试件的抗震试验,可得如下结论.1)覆板后节点破坏由墙-楼板连接处的自攻螺钉失效导致,防止该区域的自攻螺钉失效是连接成败的关键. 2)覆板后规程推荐节点承载力、耗能能力明显提高,但受截面高度、轴压比的影响均较大. 3)覆板后角钢加强型节点承载力及耗能能力均降低,且受截面高度的影响大;2 mm厚角钢试件在加载初期发生两肢间夹角的拉大与减小,破坏时螺钉全部从墙架柱拉脱;4 mm厚角钢试件楼层梁与角钢间的自攻螺钉过早发生失效,造成角钢厚度增加,承载力降低. 4)获得节点的恢复力骨架曲线特征值,为结构基于简化力学模型抗震计算提供基础数据.

A total of 7 samples were designed to examine the effects of different tectonic modes,axial compression ratio,cross section of the frame column and stressed-skin effect on the seismic performance.Results showed as follows.1)The joint’s failure after skinned is caused by the failure of the self-tapping screws at the wall-floor joint,so preventing the failure of self-tapping screws in the connection is key to success.2)The bearing capacity and energy dissipation capacity of the recommended joints after covering plate are obviously improved.But the bearing capacity and the energy dissipation capacity are greatly influenced by the height of the section and the ratio of axial pressure.3)The bearing capacity and energy dissipation capacity of the strengthened joint of angle steel are reduced after skinned,and are greatly effected by the height of cross section.The angle of 2mm thick specimen is enlarged and reduced in the initial loading.Until all screws are removed from the wall frame and connection completely loses its bearing capacity.Premature failure of self-tapping screws between floor beam and 4mm thick angle steel specimen causes the bearing capacity to decrease when the thickness increases.4)The joint’s skeleton curve model is obtained,and the basic data is provided for the structural calculation based on simplified mechanical model seismic performance.