装配式组合梁桥开孔钢板连接件抗剪性能

为建立适用于装配式钢-混组合梁桥的间断式开孔钢板连接件的极限承载力和初始刚度的设计计算方法，共设计3组8个间断式开孔钢板连接件与1个传统开孔钢板连接件推出试件，分别研究端部承压面、开孔孔径、贯穿筋直径与混凝土强度对间断式开孔钢板连接件的极限承载力及初始刚度的影响；利用非线性有限元模型对间断式开孔钢板连接件的受力机理、破坏过程和承载能力进行仿真模拟，并通过与试验结果进行对比分析验证仿真结果的可靠性；以试验中的变量设置为基础，增加参数取值范围，建立并分析162个非线性实体有限元模型，通过对分析结果进行多变量回归分析，提出适用于间断式开孔钢板连接件的初始刚度及极限承载力的计算表达式。结果表明：间断式开孔钢板连接件的荷载-滑移曲线分为弹性段、塑性段及下降持力段3个阶段，前2个阶段荷载主要由孔中混凝土隼、贯穿筋及端部承压混凝土共同平衡，下降持力段荷载则主要由上侧贯穿筋承担；试件极限承载力及初始刚度约为同尺寸传统开孔钢板连接件的2倍，并随开孔孔径、贯穿筋直径与混凝土强度的增加而提高；所建立的初始刚度与极限承载力计算公式与试验值吻合较好，研究结果对间断式开孔钢板连接件在装配式钢-混组合梁桥中的应用具有参考价值。

Shear Behavior of Perfobond Rib Shear Connectors for Pre-fabricated Composite Bridges

A method is established for calculating the ultimate bearing capacity and initial stiffness for discontinuous perfobond rib connectors applied to prefabricated concrete and steel composite bridges. Three sets of eight discontinuous perfobond rib connectors and a set of common perfobond rib connectors were designed to study the influences of the end-bearing surface, diameter of hole, rebar, and strength of concrete on ultimate bearing capacity and initial stiffness. Combined with the nonlinear finite element model, the reliability of which was confirmed by test results, the stress mechanism and failure process of discontinuous perfobond rib connectors were analyzed. Based on the parameter design of push-out tests, a total of 162 finite element models were established and tested. Moreover, multivariate regression analysis was carried out from the analysis results, and formulas for calculating initial stiffness and ultimate bearing capacity of discontinuous perfobond rib connectors were presented. From this research it can be concluded that the load-slip curve of discontinuous perfobond rib connector includes an elastic working stage, a plastic stage, and a decline stage. During the first two stages, load is mainly balanced among the concrete falcon shear counteract, transverse rebar bending resistance, and bottom bearing. Only the upper transverse rebars still work in the decline stage. The ultimate bearing capacity and initial stiffness of discontinuous perfobond rib connectors are approximately two times more than those for the common perfobond rib connector, and these increase with the increase of the diameter of the hole, rebar, and strength of concrete. The established initial stiffness and ultimate bearing capacity calculation formulae are in good agreement with the test results, which have reference value for the application of discontinuous perfobond rib connectors to the field of prefabricated concrete and steel composite bridges.