Considerable research progress has been made in the investigation of the structural performance of steel and composite members with round-ended oval hollow sections (ROHSs). However, few studies have focused on the joint behaviour of ROHSs, despite their advantages, i.e. high structural efficiency, excellent flow smoothness, and outstanding aesthetic appearance. This paper presents a series of experimental studies on thin-walled ROHS tubular joints, including seven T-joint and six K-joint specimens, under axial compression. The effects of key design parameters, such as the ratio of the brace diameter to the chord width (β), gap distance (g), and orientations and angles between the ROHS chord and brace, on the joint performance were investigated. Then, detailed investigations of the failure patterns, ultimate strength, initial stiffness, strain responses, ductility indices, and strength feature indices of the ROHS tubular joints were performed. The failure modes identified via axial compression tests of thin-walled ROHS tubular joints were primarily chord face plastification, weld fracture, and chord local buckling. The ultimate strength and the initial stiffness of the thin-walled ROHS tubular joint were significantly affected by the orientation between the chord and the brace owing to the novel structural feature of the round-ended oval cross-section. Compared with the predicted strengths of the axially loaded circular and rectangular hollow section tubular joints, the ROHS tubular joint exhibited a higher compression resistance because of its reasonable intersecting scheme. Finally, an assessment method for predicting the axial compression resistance of the ROHS tubular joint was proposed on the basis of the equivalent method and existing design provisions (i.e. the CIDECT-2009, GB50017-2017, AISC360-16, and EN-1993-1-8 specifications).

在研究具有圆形端部椭圆形空心截面（ROHS）的钢和复合构件的结构性能方面，已经取得了可观的研究进展。然而，尽管有ROHS的优点，即高结构效率，出色的流动平滑性和出色的美学外观，但很少有研究关注ROHS的联合行为。本文介绍了在轴向压缩下对薄壁ROHS管状接头的一系列实验研究，包括七个T型接头和六个K型接头样品。关键设计参数的影响，例如撑杆直径与和弦宽度之比（β），间隙距离（g），并研究了ROHS弦和支撑之间的方向和角度对接头性能的影响。然后，对ROHS管接头的破坏模式，极限强度，初始刚度，应变响应，延性指标和强度特征指标进行了详细研究。通过薄壁ROHS管状接头的轴向压缩测试确定的失效模式主要是弦面塑化，焊缝断裂和弦局部屈曲。由于圆头椭圆形截面的新颖结构特征，薄壁ROHS管状接头的极限强度和初始刚度受弦和撑杆之间的方向影响很大。与轴向载荷的圆形和矩形空心截面管状接头的预计强度相比，ROHS管接头具有合理的相交方案，因此具有较高的抗压强度。最后，在等效方法和现有设计规定（即CIDECT-2009，GB50017-2017，AISC360-16和EN-1993-1）的基础上，提出了一种评估ROHS管接头轴向抗压强度的评估方法。 -8规格）。