集束式长短剪力钉抗剪承载力计算方法

为给新型预制拼装钢-混组合梁桥设计施工提供参考，针对该类桥采用集束式长短剪力钉的布置特点，考虑剪力钉不同直径、长度、强度和混凝土强度等因素，开展集束式长短剪力钉的抗剪性能、极限承载能力有限元分析和试验研究。采用推出试验的方法，设计制作18个剪力钉推出试件，考察剪力钉长度和直径对集束式长短剪力钉抗剪极限承载力的影响，提出集束式长短剪力钉的群钉荷载-滑移曲线公式。同时，考虑混凝土、剪力钉、钢梁和钢筋的材料非线性，采用ANSYS软件建立推出试验的有限元模型，分析混凝土强度、剪力钉强度、剪力钉相对位置、混凝土板厚等参数对集束式长短剪力钉抗剪力学性能的影响规律，提出集束式长短剪力钉的单钉极限抗剪承载力计算公式。研究结果表明：短剪力钉的直径和抗拉强度、混凝土强度对集束式长短剪力钉的抗剪承载力和刚度有明显影响；而短剪力钉的长度、长短剪力钉的相对布置位置和混凝土板厚对集束式长短剪力钉的抗剪承载力和刚度影响较小；提出的计算公式计算值与试验值吻合较好。

Calculation Method of Shear Capacity of Clustered Stud Connectors with Different Lengths and Diameters

To provide a reference for the design and construction of a new prefabricated steel-concrete composite bridge, this study examined clustered shear studs with different lengths and diameters constructed for this bridge. The diameter, length, and strength of shear studs, as well as the strength of concrete, were considered by employing finite element analysis. In addition, an experimental study of the shear performance of clustered shear studs was conducted. Through the pull-out test method, 18 specimens were designed to determine the effects of the lengths and diameters of shear studs on the ultimate shear capacity of clustered shear studs, and a calculation formula for a load-slip curve was proposed. Simultaneously, considering the material nonlinearity of concrete, shear stud, steel beam and steel bar, a finite element model of the pull-out test specimen was established using ANSYS software. Based on a parameter analysis, the effects of the concrete strength, shear stud strength, relative position of shear studs, and concrete slab thickness on the shear mechanical properties of the clustered shear studs were investigated. A calculation formula for the ultimate shear capacity of a single shear stud in the clustered shear studs was also proposed. Results demonstrate that the diameter and tensile strength of shear stud and the strength of concrete have considerable influence on the shear capacity and stiffness of clustered shear studs, whereas the effect of the length and relative position of shear studs as well as the thickness of the concrete slab are negligible. Finally, the calculation results of the two proposed formulae were observed to agree well with the experimental values.