This paper presents a computational model for determining the axial responses of circular Steel-Reinforced Concrete-Filled Steel Tubular (SRCFST) short columns. A novel confinement model is formulated for the concrete-core that is effectively confined by the external circular steel tube and the embedded steel section. The modeling scheme of confinement is programmed in the mathematical model that utilizes the fiber element discretization of column cross-sections. The numerical predictions are verified by experimental measurements and results obtained from the finite element analysis, demonstrating the accuracy of the modeling technology. In addition, existing concrete confinement models for concrete in circular Concrete-Filled Steel Tubular (CFST) columns are assessed. The new confinement model is shown to be superior in replicating the responses of SRCFST columns. The influences of design parameters on the column's performance are numerically investigated and the importance order of these parameters is determined by a sensitivity analysis. The study not only examines the validity of current design standards in determining the axial load capacity of SRCFST columns but also proposes a new design formula. The proposed confinement model can be employed in numerical procedures for the inelastic simulation of SRCFST columns and the design formula is suitable for use in practical design.

中文翻译：

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轴压圆形钢管混凝土短柱数值模拟与设计

本文提出了一种计算模型，用于确定圆形钢管混凝土（SRCFST）短柱的轴向响应。为混凝土核心筒制定了一种新颖的约束模型，该模型由外部圆形钢管和嵌入钢型材有效约束。约束建模方案在利用柱横截面纤维单元离散的数学模型中进行编程。数值预测通过实验测量和有限元分析结果得到验证，证明了建模技术的准确性。此外，还评估了圆形钢管混凝土 (CFST) 柱中混凝土的现有混凝土约束模型。新的限制模型在复制 SRCFST 柱的响应方面表现出优越性。对设计参数对色谱柱性能的影响进行了数值研究，并通过灵敏度分析确定了这些参数的重要性顺序。该研究不仅检验了现行设计标准在确定 SRCFST 柱轴向承载能力方面的有效性，而且提出了一种新的设计公式。所提出的约束模型可用于SRCFST柱非弹性模拟的数值程序，并且设计公式适合在实际设计中使用。