SummaryConcrete‐encased columns reinforced with one built‐up steel core are widely used as mega columns in high‐rise buildings. Due to the enormous size of the steel core, multiple steel segments have to be welded and spliced on‐site, which might inflict detrimental impacts on the integrity and ductility of the columns. To solve this practical issue, one method using multiple steel sections to replace one gigantic built‐up section is proposed. However, whether those columns reinforced with individual steel sections could have the same capacity as the ones reinforced with one steel core and whether the current design method relying on strain compatibility is still applicable to design such columns remain unknown. In this study, one column specimen reinforced with multiple steel sections is tested and the test results are utilized to calibrate finite element models. Afterward, finite element (FE) analysis is performed on concrete‐encased columns reinforced with multiple steel sections to numerically examine the load capacity of those columns. Based on the numerical analysis, a design method based on modified strain distribution is proposed. Numerical results indicate that concrete‐encased columns reinforced with multiple steel sections exhibit similar performance compared with the one reinforced with one steel core, showing great potential to be applied as mega columns in high‐rise buildings.

中文翻译：

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多型钢加固混凝土围柱的有限元分析

摘要 用一根组合钢芯加固的混凝土包裹柱被广泛用作高层建筑中的巨型柱。由于钢芯尺寸巨大，必须在现场焊接和拼接多个钢段，这可能会对柱的完整性和延展性造成不利影响。为了解决这一实际问题，提出了一种使用多个钢型材代替​​一个巨大组合型材的方法。然而，单根型钢加固的柱能否具有与一根钢芯加固的柱相同的承载力，以及目前基于应变相容性的设计方法是否仍然适用于此类柱的设计，仍是未知数。在本研究中，对由多个钢截面加固的一根柱试件进行了测试，并利用测试结果来校准有限元模型。随后，对用多个型钢加固的混凝土包裹柱进行有限元 (FE) 分析，以数值方式检查这些柱的承载能力。在数值分析的基础上，提出了一种基于修正应变分布的设计方法。数值结果表明，多型钢加固的混凝土包裹柱与单芯加固的混凝土包裹柱表现出相似的性能，在高层建筑中作为巨型柱具有巨大的应用潜力。