In this study, the collapse-resistant performance of two, one-third scale composite beam–column substructures, with bolt and welded (WUF) connections and cover plate reinforced (WUFG) connections, were investigated by performing quasi-static tests. The experimental results demonstrated that the cover plate of the WUFG connections contributes to an increased displacement and bearing capacity in comparison with that of the WUF connections. Additionally, in comparison with the corresponding steel substructures, the maximum bearing capacities of the WUF and WUFG increased by approximately 18.0% and 19.9%, respectively. Multi-scale modeling method, which combined different types of elements with a reasonable connection, using the principle of displacement consistency, was calibrated by the experimental results. The results revealed that multi-scale models not only ensured the accuracy of the model calculation results, but also significantly improved the calculation efficiency. Based on the validated models, the influence of the surrounding members on the collapse-resistant performance of the composite beam–column substructure was analyzed. The results indicated that the axial constraint provided by the surrounding members demonstrated a greater impact on the collapse-resistant performance of the beam–column substructures in a certain range. Moreover, the multi-scale models were further extended to study the effect of important parameters on the collapse-resistant performance of the beam–column substructures, including the beam height, the beam span, the boundary condition, and the outermost column section, after which suitable ranges of these parameters were suggested.

在这项研究中，通过进行准静态测试，研究了两个三分之一比例的组合式梁柱组合结构（具有螺栓和焊接（WUF）连接和盖板增强（WUFG）连接）的抗倒塌性能。实验结果表明，与WUFG连接相比，WUFG连接的盖板有助于增加位移和承载能力。此外，与相应的钢子结构相比，WUF和WUFG的最大承载能力分别增加了约18.0％和19.9％。实验结果对多尺度建模方法进行了校准，该模型采用位移一致性原理将不同类型的元素合理连接在一起。结果表明，多尺度模型不仅保证了模型计算结果的准确性，而且大大提高了计算效率。在验证模型的基础上，分析了周围构件对梁柱组合结构抗倒塌性能的影响。结果表明，在一定范围内，周围构件提供的轴向约束对梁柱子结构的抗倒塌性能产生较大影响。此外，进一步扩展了多尺度模型，以研究重要参数对梁柱子结构抗倒塌性能的影响，包括梁高度，梁跨度，边界条件和最外柱截面，