直立锁边金属屋面系统关键连接节点抗拉承载力试验

针对直立锁边金属屋面系统的固定支座与檩条连接节点的抗拉承载力计算问题，以檩条翼缘板厚、檩条材质、自攻螺钉直径、自攻螺钉数量以及固定支座底板厚度为变量，进行了92个连接节点试件的受拉试验，研究连接节点在竖向拉荷载下的破坏现象及破坏模式。对已有固定支座与檩条连接节点的抗拉承载力计算公式进行了修正，并将抗拉承载力试验值与国内外规范的计算值进行了对比。结果表明:自攻螺钉的抗拉承载力与檩条翼缘板厚、檩条材质的抗拉强度、自攻螺钉直径、螺钉数量基本呈正比关系，固定支座底板厚度大于4 mm时，螺钉抗拉承载力与固定支座底板厚度相关性较小；节点存在自攻螺钉被拉出、固定支座底板被拉弯和自攻螺钉被拉出、固定支座底板被拉弯和自攻螺钉在螺帽处被拉断3种破坏模式；根据国内外规范公式得到的节点抗拉承载力计算值比试验值偏小，工程应用偏于安全。

Tension Bearing Capacity of Key Connections of Standing Seam Metal Roofing System

In view of the calculation problems of tension bearing capacity on the connection of fixed support and purlin of standing seam metal roofing, taking the purlin flange thickness, purlin material, diameter of self tapping screw and plate thickness of fixed support as the variables, the tension tests of 92 connection specimens were carried out. Failure phenomena and failure modes of connections under vertical tensile load were investigated. The tension bearing capacity calculation formulas of the connection of fixed bearing and purlin were corrected. The test values of tension bearing capacity were compared with the calculation values of codes at home and abroad. The results indicate that the tension bearing capacity of the self tapping screw is proportional to the purlin flange thickness, purlin material tension strength, diameter of self tapping screw and number of screw. When the bottom plate thickness of fixed support is more than 4 mm, the bearing capacity of screw has little correlation with the bottom plate thickness of fixed support. There are three failure modes including the self tapping screws being pulled out, the bottom plate of fixed support being bent and self tapping screws being pulled out, bottom plate of fixed support being bent and self tapping screws being broken at nut because of pulling. The calculated values of tension bearing capacity of connection at home and abroad are smaller than test values, so the engineering application is safety.