Experimental evaluation of the structural behaviour of concrete-filled tubular (CFT) circular steel columns under the combined effects of axial and cyclic lateral loads is costly and challenging. This study provides a non-linear finite-element analysis (FEA) of 21 models of CFT circular steel columns wrapped with several carbon-fibre-reinforced polymer (CFRP) composite layers at the end region, which represents the critical location in terms of lateral load capacity. The intent is to confine the column end to avoid outward local buckling of the column and thus develop high strength, larger net drift and more energy dissipation. The non-linear FEA models were properly calibrated and validated with reputable experimental results; a parametric study was then conducted to assess the influence of the number of CFRP layers and axial load level on CFT circular steel column performance. Also, it was found that the column axial load level significantly affects the CFT circular steel column behaviour under lateral loading, behaviour improved as the axial load level increased. It takes a parametric investigation, in terms of strengthening system, and the findings of this study provide a useful guideline and methodology for similar strengthening of CFT steel columns.

中文翻译：

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CFRP包裹钢管混凝土柱的有限元模拟

在轴向和循环侧向荷载共同作用下，对钢管混凝土（CFT）圆钢柱的结构性能进行实验评估既昂贵又具有挑战性。这项研究提供了21种CFT圆形钢柱模型的非线性有限元分析（FEA），在末端区域包裹了数个碳纤维增强聚合物（CFRP）复合层，代表了侧向的关键位置装载能力。目的是限制色谱柱末端，以避免色谱柱向外局部屈曲，从而提高强度，增大净漂移并消耗更多能量。非线性FEA模型已正确校准，并以良好的实验结果进行了验证；然后进行了参数研究，以评估CFRP层数和轴向载荷水平对CFT圆形钢柱性能的影响。此外，还发现，在轴向载荷下，柱的轴向载荷水平会显着影响CFT圆形钢柱的性能，随着轴向载荷水平的增大，柱性能会有所改善。在加强系统方面进行了参数研究，这项研究的结果为类似的CFT钢柱加强提供了有用的指导和方法。