Strength and Stiffness of Circular Concrete-Filled Tubes
Strength and Stiffness of Circular Concrete-Filled Tubes
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DOI：
10.1061/(asce)st.1943-541x.0000263
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发表时间：
2010-12-01
期刊：
影响因子：
--
通讯作者：
Bishop, Erik
中科院分区：
文献类型：
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作者：
Roeder, Charles W.;Lehman, Dawn E.;Bishop, Erik
钢管混凝土是由钢管和混凝土填充物组成的组合结构构件。CFTS通过提高它们的几何效率和充分利用它们的固有优势来优化这两个组成部分的贡献。混凝土填充物被钢管限制，导致三轴压缩状态，从而增加混凝土的强度和应变能力。周边钢筋处于最佳位置，混凝土填充延迟了钢管的局部和整体屈曲。CFT易于快速建造，并具有显著的抗压、抗弯曲和抗剪切性能。它们可用于桥墩和建筑立柱。然而，目前CFT的设计规范差异很大，从而限制了目前对这些组件的理解和使用。这项研究考虑了轴向和弯曲荷载的组合，并确定了预测圆形钢管混凝土的刚度和抗力的最佳模型。编制了一个包含122个测试样本的数据库并进行了评估。结果表明，塑性应力法是预测圆形钢管混凝土构件在复合荷载作用下抗力的一种简单而有效的方法。这些数据表明，现行规范对抗弯刚度的预测是不准确的，并提出了一个新的刚度表达式。建议的模型允许简单而准确地预测刚度和阻力，并允许工程师在结构设计中常规使用CFT组件。
Concrete-filled tubes (CFTs) are composite structural members that consist of a steel tube and concrete infill. CFTs optimize the contributions of both components by improving their geometric efficiency and fully using their inherent strengths. The concrete infill is confined by the steel tube, resulting in a triaxial state of compression that increases the strength and strain capacity of the concrete. The perimeter steel is at its optimal location, and the concrete infill delays local and global buckling of the tube. CFTs are easily and rapidly constructed and provide significant compression, bending, and shear resistance. They may be used for bridge piers and building columns. However, current design specifications for CFTs vary significantly, thereby limiting the current understanding and use of these components. This study addresses combined axial and flexural loading and determines the best models for predicting the stiffness and resistance of circular CFT. A database of 122 test specimens was compiled and evaluated. The results indicate that the plastic stress method is a simple yet effective method to predict the resistance of circular CFT components under combined loading. These data show that current specifications provide inaccurate predictions of the flexural stiffness, and a new stiffness expression is proposed. The proposed models permit simple yet accurate predictions of stiffness and resistance and allow engineers to use CFT components routinely in structural design.