Experimental study of cold-formed steel built-up columns
Experimental study of cold-formed steel built-up columns
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DOI：
10.1016/j.tws.2019.106291
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发表时间：
2020-04
影响因子：
6.4
通讯作者：
F. Meza;Jurgen Becque;I. Hajirasouliha
中科院分区：
文献类型：
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作者：
F. Meza;Jurgen Becque;I. Hajirasouliha
设计了一个全面的实验方案，目的是研究冷弯型钢组合柱的行为和能力，特别强调连接器间距和单个组件之间接触的影响。共有24根组合柱，包括四种不同的截面几何形状，在销端边界条件下进行了测试，同时施加额定偏心距为l /1000或l /1500的载荷。柱的破坏模式包括构件的截面屈曲、连接件间构件可能的整体屈曲和柱的整体屈曲，并成功地实现了这些破坏模式。建筑部分由平板、平面通道和唇形通道组成，并用螺栓或自钻螺钉组装。接头间距在相同截面几何形状的试样之间是不同的。为了确定其材料性能，从平面部分和截面的角处取下拉伸试样，同时使用专门设计的测量装置对每个试样的几何缺陷进行了详细测量。此外，通过单搭接剪切试验研究了试件中使用的螺栓和螺钉的隔离行为。结果表明，组合试件的屈曲模式受各构件之间的接触和连接件之间的间距影响。然而，在连接点之间构件的整体屈曲不严重的情况下，连接点间距对柱的极限承载力影响较小。
A comprehensive experimental programme was contrived with the aim of investigating the behaviour and the capacity of cold-formed steel built-up columns with particular emphasis on the effects of connector spacing and contact between individual components. A total of 24 built-up columns, including four different cross-sectional geometries, were tested between pin-ended boundary conditions, while applying the load with nominal eccentricities ofL/1000 orL/1500. The columns were designed to fail by interaction of cross-sectional buckling of the components, possible global-type buckling of the components between connectors and global buckling of the whole column, and all these failure modes were successfully achieved. The built-up sections were fabricated from flat plates, plain channels and lipped channels and were assembled with either bolts or self-drilling screws. The connector spacing was varied between specimens of the same cross-sectional geometry. Tensile coupons were taken from the flat portions and the corners of the sections in order to determine their material properties, while detailed measurements of the geometric imperfections of each specimen were also carried out using a specially designed measuring rig. In addition, the isolated behaviour of both the bolts and the screws used in the specimens was investigated through single lap shear tests. It was observed that the buckling patterns in the built-up specimens were affected by contact between the various components and by the spacing between the connectors. However, in the cases where global buckling of the components in between connector points was not critical, the connector spacing had a minor influence on the ultimate capacity of the columns.