复合剪力连接件群钢-混结合段力学性能

为研究复合剪力连接件群钢-混结合段的力学性能，以我国首座铁路混合梁斜拉桥为研究背景，通过数值模拟与模型试验相结合的方法研究了钢-混结合段及其复合剪力键群的静力和疲劳性能。结果表明：需注重钢-混结合段的构造细节处理以避免产生局部应力集中现象；剪力钉较PBL剪力键起主要传剪作用，与复合剪力键群形式相比，只采用PBL剪力键传剪会增大承压板传力负荷；底板剪力钉受形式与推出试验结果一致，由于混凝土浇筑质量等原因，顶板剪力钉受力形式与推出试验有一定差异；在疲劳试验后，受力较大的底板剪力钉根部应力水平增大较多，进入弹塑性受力状态，受力较大的PBL剪力键应力水平有所增大，但整体应力水平较低。可见采用复合剪力键形式的钢-混结合段受力合理，其设计可以为其他同类工程提供参考。

Study on Mechanical Properties of Steel-Concrete Joint Section with Composite Shear Connectors

In order to study the mechanical properties of steel-concrete joint section of composite shear connectors, the first railway hybrid girder cable-stayed bridge in China was taken as the research background, and numerical simulation and model test were used to investigate the static and fatigue properties of steel-mixed bond concrete joint section and its composite shear connectors. The results show that it is necessary to pay attention to the structural details of steel- concrete joint section to avoid local stress concentration. The shear studs play a major role in shear transmission. Compared with the composite shear connectors, the load of the bearing plate will increase with only PBL shear connector used. The mechanical behavior of the shear studs at the bottom plate is consistent with the results of the push out test, while the mechanical behavior of the shear studs at the top plate is different from the results of the push out test due to the quality of concrete pouring. After the fatigue test, the stress level of the shear stud under greater stress at the bottom plate increases more and enters the elastic-plastic stress state. The stress level of the PBL shear connectors under greater stress increases, but the overall stress level is low. It is concluded that the steel-concrete joint section with composite shear connectors has rational mechanical behavior, and its design can provide reference for other similar projects.