冷弯型钢类地聚物泡沫混凝土柱轴压性能

Axial compression performance of cold-formed steel-geopolymer foam concrete column

摘要:

为抑制冷弯型钢柱的屈曲变形及提高其承载力,对冷弯型钢-类地聚物泡沫混凝土组合柱的受力性能采用试验、数值仿真和理论相结合的方法进行系统性研究。对构件的荷载-轴向位移曲线、试验过程及破坏特征进行分析。比较不同形式构件的破坏模式及承载力结果,探讨不同因素对构件轴压性能的影响。结果表明:组合柱极限承载力相比拼合柱提高了1.4倍；板件宽厚比为60~100时,类地聚物泡沫混凝土利用率较高；泡沫混凝土密度每提高一个等级,组合柱的极限荷载约增加1.5%；从用钢量的角度考虑,设置对称单肋对组合柱极限承载力的提高更明显。在试验和数值仿真的基础上,依据现有相关规范中的计算方法对组合柱极限承载力进行了计算,发现JGJ 138—2016《组合结构设计规范》^[1]给出的计算方法可粗略估计组合柱极限承载力。最后,提出适用于组合柱轴压承载力的计算方法,并验证该公式的准确性。

Abstract:

In order to suppress the buckling deformation and enhance bearing capacity of cold-formed steel columns, a systematic study was conducted using a combination of experimental testing, numerical simulation, and theoretical analysis on cold-formed steel-geopolymer foam concrete composite columns. The load-axial displacement curves, test process and failure characteristics of the members were analyzed. The failure modes and bearing capacity results of different types of members were compared and the effects of different factors on the axial compression performance of the members were discussed. The results show that: the ultimate bearing capacity of the composite column is 1.4 times higher than that of the CFS built-up column. When the width-thickness ratio is in the range of 60-100, the utilization rate of geopolymer foam concrete is higher. For every increase in the density of foam concrete, the ultimate load of the composite column increases by about 1.5%. From the perspective of steel consumption, the setting of symmetrical single ribs has a more significant impact on enhancing the ultimate bearing capacity of composite columns. Based on the experiment and numerical simulation, the ultimate bearing capacity of composite columns is calculated according to the calculation methods in existing relevant codes. It is found that the calculation method given by the ′Code for design of composite structures′ can roughly estimate the ultimate bearing capacity of the composite columns. Finally, a calculation method suitable for the axial compression bearing capacity of the composite columns is proposed, and the accuracy of the formula is verified.