In typical square tubular joints, the most common failure mode is local yielding or buckling of the chord at the brace/chord intersection. Thus, in the current paper, a collar-plate, as external reinforcement, is welded around the weld toe to increase the stiffness of the chord surface. Firstly, theoretical formulas, based on the yield line principle which is often used to examine thin-walled members suffering from local collapse mechanisms, for calculating the capacities of the collar-plate-reinforced square tubular T-joints under axial compression and in-plane bending are deduced. Then, experimental tests and finite element (FE) simulations are carried out on square tubular T-joints reinforced with collar-plates. The experimental results showed an improvement in the bearing capacity of SHS joints reinforced with collar-plate by 78 and 89% compared with the corresponding un-reinforcement joints. The FE results, as well, proved that using the collar-plate reinforcement is an efficient method to improve the static strength of a square tubular T-joint under either axial compression or in-plane bending. Finally, through the comparison between the FE results and the theoretical formulas, the validation range of the formulas for predicting the strengths of the collar-plate-reinforced square tubular T-joints is specified. For the joints under axial pressure, the validation range of the proposed formula is 0.45 ≤ β c ≤ 0.8, 2 γ ≥ 20 and τ c ≥ 1.5, while for the joints under in-plane bending is β c ≤ 0.8, 15 ≤ 2 γ ≤ 30 and τ c ≥ 1.50.

中文翻译：

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在轴向压缩或平面弯曲下用领板加固的方形 T 型接头的静态强度

在典型的方管接头中，最常见的失效模式是在支撑/弦杆交叉处的弦杆局部屈服或屈曲。因此，在当前的论文中，作为外部加强件的领板被焊接在焊趾周围以增加弦表面的刚度。首先，基于屈服线原理，常用于检验薄壁构件遭受局部坍塌机制的理论公式，用于计算轴压和平面内轴压方管T型接头的承载力弯曲推断。然后，对用领板加固的方管 T 型接头进行实验测试和有限元 (FE) 模拟。试验结果表明，与相应的未加固节点相比，采用轴环板加固的 SHS 节点的承载能力分别提高了 78% 和 89%。有限元结果也证明，使用领板加固是提高方管 T 型接头在轴向压缩或面内弯曲下的静态强度的有效方法。最后，通过有限元结果与理论公式的比较，确定了用于预测领板加固方管T型接头强度的公式的验证范围。对于轴压接头，建议公式的验证范围为0.45 ≤ β c ≤ 0.8, 2 γ ≥ 20 和τ c ≥ 1.5，而面内弯曲接头的验证范围为β c ≤ 0.8, 15 ≤ 2 γ ≤ 30 且 τ c ≥ 1.50。