In this paper, the structural behavior of concrete-filled double steel tubular (CFDST) stub columns composed of square hollow sections is investigated experimentally and numerically. The experimental program comprises compression tests on short columns loaded concentrically. The test parameters mainly focused on the influences of the width-to-thickness ratios of steel tubes and concrete strength on the axial behavior of CFDST stub columns. Finite element (FE) models are also developed to investigate the influences of a wide range of structural parameters on their axial performance. It is observed that square CFDST columns have improved strength and ductility compared to their CFST and DCFST counterparts. Finally, a calculation formula is proposed to predict their ultimate compressive strengths under the axial compression load.

本文通过实验和数值研究，研究了由方形空心截面组成的钢管混凝土（CFDST）短柱的结构性能。实验程序包括对同心加载的短柱的压缩测试。试验参数主要集中在钢管的宽厚比和混凝土强度对CFDST短柱的轴向性能的影响上。还开发了有限元（FE）模型来研究各种结构参数对其轴向性能的影响。可以看到，与CFST和DCFST对应的方柱相比，方形CFDST柱具有更高的强度和延展性。最后，提出了计算公式来预测其在轴向压缩载荷下的极限抗压强度。