基于试验和规范预测冷弯Z型钢组合柱的整体抗压性能

对冷弯型钢组合构件进行压缩试验,以确定比利时工程实践中的常用构件———双Z型钢柱的整体抗压性能。对8组4.45m的长柱进行全尺试验,并记录每个样本6个点处的平面外位移和应变。根据柱高中点处的线应变评估初始缺陷的影响。采用欧洲钢结构规范将所得到的极限性能和预测方法相结合。对预测分析中的假定以及规范中的差异进行了解释与探讨。由于范围受限,构件中的某些性能无法使用欧洲规范进行预测。还可使用北美规范进行冷弯型钢构件设计,其所提供的设计方法略有优势。提出了EN1993-1-3∶2006修正方法,以及基于直接强度法的设计方法。

Composed Columns from Cold-Formed Steel Z-Profiles:Experiments and Code-Based Predictions of the Overall Compression Capacity

Built-up cold-formed steel members are tested in compression. The main objective behind the experiments is to determine the overall compression capacity of double-Z columns, which are often used in the Belgian engineering practice. Eight full-scale tests on 4.45 m long columns are performed and out-of plane displacements and strains at six locations per member are recorded. The effect of initial imperfections is evaluated based on the measured longitudinal strains at mid-height. An attempt to relate the obtained ultimate capacity to prediction methods, based on the European standard for steel structures and, is presented. The assumptions made in the analytical prediction and the gaps within the cited standard are explained and discussed. Certain aspects of the behaviour of such members cannot be represented in an Eurocode-base prediction, due to the restricted scope of and. A reference is made to North American Specification for the design of cold-formed steel structural members as well, where a slightly better design methodology is available. Amendments to EN 1993-1-3∶2006 are proposed and a design approach, based on the direct strength method is presented.