In this study, a type of steel–concrete–steel (SCS) composite deep beam with ultra-high-performance concrete, named S-UHPC deep beam, was developed. Eight simply supported deep beams, including three SCS deep beams and five S-UHPC deep beams, were tested under static loads. The effects of different parameters (including the shear span ratio, concrete type, and shear stud spacing) on the ultimate capacity, ductility, and interfacial slip of the specimens were explored. Moreover, the observed failure modes were categorized into shear failure without slip, slip failure, and flexural failure with the snapping of steel fibers. To analyze the failure mechanism systematically, finite element (FE) models of the specimens were established and validated. By analyzing the FE simulation results on the compressive damage and stress distribution of the filled concrete, the von Mises stress distribution of shear studs, and the equivalent plastic strain distribution of the bottom steel faceplate, the failure mechanism of the specimens with the observed failure modes was simplified as a modified Strut-and-Tie model. Based on the force transfer analysis of the modified Strut-and-Tie model, a slip coefficient was deduced to quantify the composite action and provide theoretical supports for the reasonable design of shear connectors. Theoretical models of SCS deep beams and S-UHPC deep beams with different failure modes were presented to predict the ultimate capacity.

在这项研究中，开发了一种具有超高性能混凝土的钢-混凝土-钢（SCS）复合深梁，称为 S-UHPC 深梁。八根简支深梁，包括三根SCS深梁和五根S-UHPC深梁，在静载荷下进行了测试。探讨了不同参数（包括剪跨比、混凝土类型和剪力钉间距）对试件的极限承载力、延性和界面滑移的影响。此外，观察到的破坏模式分为无滑动的剪切破坏、滑动破坏和钢纤维折断的弯曲破坏。为了系统地分析失效机制，建立并验证了试件的有限元 (FE) 模型。通过对填充混凝土的压缩损伤和应力分布、剪力钉的von Mises应力分布以及底部钢面板等效塑性应变分布的有限元模拟结果进行分析，分析了具有观察破坏模式的试件的破坏机制被简化为修改后的 Strut-and-Tie 模型。在对改进的Strut-and-Tie模型进行力传递分析的基础上，推导出滑移系数，量化复合作用，为剪力连接件的合理设计提供理论支持。提出了具有不同破坏模式的SCS深梁和S-UHPC深梁的理论模型来预测极限容量。具有观察到的失效模式的试样的失效机制被简化为改进的 Strut-and-Tie 模型。在对改进的Strut-and-Tie模型进行力传递分析的基础上，推导出滑移系数，量化复合作用，为剪力连接件的合理设计提供理论支持。提出了具有不同破坏模式的SCS深梁和S-UHPC深梁的理论模型来预测极限容量。具有观察到的失效模式的试样的失效机制被简化为改进的 Strut-and-Tie 模型。在对改进的Strut-and-Tie模型进行力传递分析的基础上，推导出滑移系数，量化复合作用，为剪力连接件的合理设计提供理论支持。提出了具有不同破坏模式的SCS深梁和S-UHPC深梁的理论模型来预测极限容量。