Abstract: Current studies on the crest bond shear connector (CR) in steel-concrete composite bridges mainly focus on the bearing capacity. Yet, few works have been done on the shear stiffness of the connector and there is no universal theoretical formula to describe the shear behavior. Therefore, experimental studies were conducted to establish a reasonable formula to calculate the shear stiffness of CR connectors, and the corresponding finite element model was then established and verified based on the experimental results. The load-displacement curves of shear connectors with different structural parameters in the elastic phase were simulated, and the variation law of elastic shear stiffness of connectors under different parameters was revealed. The equivalent spring model and equivalent rod spring model were adopted to investigate the shear stiffness of shear members, concrete tenons and steel bars penetrating through concrete tenons, respectively. The theoretical formula to calculate the elastic shear stiffness of the CR connector was derived based on the superposition relationship of stiffness in the elastic stage. The comparison between theoretical calculation and finite element fitting results shows that the error between the theoretical calculation value and the fitting value of the elastic shear stiffness of the connector is within 7.7% and the results show good consistency, which can be used as a basis for structural design.

Key words: bridge engineering; CR connector; shear stiffness; finite element; equivalent spring model; equivalent rod system spring model

摘要： 当前对于钢混组合梁桥中CR连接件的研究主要集中于承载力，对其抗剪刚度研究较少，没有较为通用的理论计算公式。为建立合理的CR连接件抗剪刚度计算公式，笔者基于现有试验建立有限元模型并加以验证，模拟不同结构参数的剪力连接件弹性阶段的荷载-位移曲线，揭示不同参数下的连接件弹性抗剪刚度变化规律。利用等效弹簧模型和等效杆系弹簧模型，笔者分别研究了剪力键、混凝土榫以及混凝土榫内贯穿钢筋的抗剪刚度，结合弹性阶段刚度叠加关系，建立了CR连接件弹性抗剪刚度理论计算公式。理论计算与有限元拟合结果对比表明：连接件弹性抗剪刚度理论计算值与拟合值的误差在7.7%以内，结果吻合性较好，可作为结构设计的依据。

关键词: 桥梁工程；CR连接件；抗剪刚度；有限元；等效弹簧模型；等效杆系弹簧模型