高强度钢材螺栓连接抗剪性能试验研究

近年来高强度钢材在工程中得到了逐步推广和应用,尤其是Q460强度等级的高强度钢材。但是目前各国规范都尚未对高强度钢材螺栓连接设计方法做出具体规定,仍沿用普通强度钢材的设计方法。因此,需对端距、边距和螺栓间距等几何构造对高强度钢材螺栓抗剪连接性能的影响进行深入的试验研究。针对10,12 mm厚的Q460强度等级的高强度钢材进行螺栓抗剪连接试验,通过改变两个10.9级M27高强度螺栓的几何布置,研究不同端距、边距和螺栓间距情况下,高强度钢材的承压性能的变化情况。由试验可以观察到螺栓抗剪连接的3种不同的破坏模式:端部撕裂、孔壁拉长和板净截面拉断。同时还将试验得到的极限承载力与欧洲和美国钢结构设计规范设计值进行比较。结果发现,现有规范并不能很好地预测高强度钢材螺栓抗剪连接的破坏模式和极限强度,建议更深入地进行参数分析以完善规范设计方法。

EXPERIMENTAL STUDY ON HIGH STRENGTH STEEL-PLATEBOLTED CONNECTIONS UNDER SHEAR FORCE

The use of high strength steel,particularly above grade Q460,has increased in recent years.But there are no regulations on bolted connections with high strength steel.Especially,there are significantly fewer investigations on the influence of end distance,edge distance or bolt spacing on the shear resistance of high strength steel in comparison to mild steel.Therefore,extensive experimental research on bolted connections made of high strength steel under static shear was put.It was tested 10 mm and 12 mm plate of grade Q460 steel.All test specimens with two M27 bolts class 10.9 bolts arranged in a transverse direction to the load axis were assembled with different dimensions to explore the influence of end distance,edge distance and bolt spacing.The objective of the research was to determine the ductility and resistance of such connections.Different failure modes of bolted connections could be observed in the test.The ultimate bearing capacity was compared with that predicted by the current connection provisions specified in Eurocode and AISC steel design standards.Recommendations concerning the adequacy of current design standards with respect to the design of high strength steel bolted connections were proposed.