Guo Jinlong, Li Pingjie, Pan Shuang, Chen Min
College of Engineering, Fujian Jiangxia University, Fuzhou, 350108, People's Republic of China.
CCCC Fourth Harbor Engineering Institute Co., Ltd., Guangzhou, 510230, Guangdong, People's Republic of China.
Sci Rep. 2025 Jul 5;15(1):24042. doi: 10.1038/s41598-025-09485-y.
Square in square concrete-filled double-skin steel tube (CFDST) columns are widely preferred on account of their convenient nodal structural form and efficient construction process. In order to investigate the axial compression behavior of the columns after lateral impact, a precise numerical model for the post-impact axial compression of square in square CFDST columns was established using the finite element package, and was validated by existing experiments and studies. The residual axial compression bearing capacity of the columns after lateral impact has been analyzed. The typical vertical load-axial displacement curve, the failure mode and stress distribution of the columns have been studied. The parametric analysis has been also carried out to explore the influence of key parameters. Lastly, based on the parametric analysis, a simplified formula has been proposed to estimate the residual axial compression bearing capacity of the columns. The results show that under lateral impact, the columns generally exhibit a flexural failure mode. Local indentation occurs at the impact location, and buckling also appears at the bottom of the fixed support section. The coefficient of residual axial compression bearing capacity decreases with the increase of impact energy, slenderness ratio, and concrete strength, and increases significantly with the increase of steel strength.
方内方钢管混凝土柱因其节点结构形式便捷、施工过程高效而备受青睐。为研究方内方钢管混凝土柱在侧向冲击后的轴压性能，利用有限元软件建立了方内方钢管混凝土柱冲击后轴压的精确数值模型，并通过现有试验和研究进行了验证。分析了柱在侧向冲击后的残余轴压承载力。研究了柱典型的竖向荷载-轴向位移曲线、破坏模式和应力分布。还进行了参数分析以探究关键参数的影响。最后，基于参数分析，提出了一个简化公式来估算柱的残余轴压承载力。结果表明，在侧向冲击作用下，柱一般呈现弯曲破坏模式。冲击位置出现局部凹陷，固定支座段底部也会发生屈曲。残余轴压承载力系数随冲击能量、长细比和混凝土强度的增加而降低，随钢材强度的增加而显著提高。
