Experimental and numerical behavior of eccentrically loaded square concrete-filled steel tubular long columns made of high-strength steel and concrete
Experimental and numerical behavior of eccentrically loaded square concrete-filled steel tubular long columns made of high-strength steel and concrete
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DOI：
10.1016/j.tws.2020.107289
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发表时间：
2021-02-01
影响因子：
6.4
通讯作者：
Feng, Yi-He
中科院分区：
文献类型：
--
作者：
Li, Guo-Chang;Chen, Bo-Wen;Feng, Yi-He
为改善钢管混凝土柱的力学性能，越来越多的钢管混凝土柱采用高强材料。本研究旨在评估高强方钢管高强混凝土长柱在偏心受压作用下的基本性能。对偏心加载HCFHSST长柱进行了一系列试验，探讨了其受力特性和破坏机理。系统地进行了数值研究，以探索柱的承载性能。同时，进行了参数化研究，分别评价了几个关键参数对HCFHSST构件强度增加因子（SIF）、P- m和P/P-0- m /M-0曲线的影响。在此基础上，建立了偏心荷载作用下HCFHSST长柱峰值荷载预测方程。将试验和模拟峰值荷载与各种设计规范和推荐公式的结果进行了比较，以评估这些计算系统的可行性。结果表明：考虑二阶效应，试件弯矩-曲率曲线可分为三种类型。数值模拟结果表明，采用高强钢可以提高柱的屈服荷载比例，且采用高强混凝土填充时，混凝土能够承受大部分荷载。通过对规范EC4、AISC 360和GB 50936的峰值荷载计算，发现规范GB 50936的峰值荷载计算结果平均较好，但在某些e/B比较高的情况下不安全。本研究提出的方程式能提供较好的预测，因此建议使用。
The high-strength materials are increasingly used in the concrete-filled steel tubular (CFST) column to improve its mechanical behaviors. This study aims to evaluate the fundamental behavior of high-strength concrete-filled high-strength square steel tubular (HCFHSST) long columns under eccentric compression. A series of tests were conducted on eccentrically loaded HCFHSST long columns to investigate the mechanical characteristics and failure mechanisms. Numerical investigations were systematically performed to explore the load-carrying performance of the column. Meanwhile, parametric studies were implemented to evaluate influences of several key parameters on the strength increase factor (SIF), P-M, and P/P-0-M/M-0 curves of the HCFHSST members, respectively. Furthermore, the equations were proposed to predict the peak-loads of HCFHSST long columns under eccentric loading. The experimental and simulated peak-loads were compared with the results of various design codes and recommended equations to assess the feasibilities of those calculation systems. The results demonstrated that the bending moment-curvature curves of the experimental specimens could be categorized into three types considering the second-order effect. Additionally, it was numerically observed that using highstrength steel can enhance the yield load proportion of the column, and the concrete withstands most of the applied load when utilizing high-strength concrete as infill. Based on the peak-load calculations of codes EC4, AISC 360, and GB 50936, it was found that code GB 50936 presented a better result on average while was unsafe for some cases with high e/B ratios. The equations proposed in this study can provide an improved prediction and hence are suggested.