组合结构桥梁钢混交界区非连续变形特征突出、局部受力复杂，其行为特性不易被掌握，抗剪连接性能设置合理与否直接关系到组合结构经济技术优势的发挥。将粘聚区模型应用于组合结构桥梁抗剪连接界面的破坏模拟，建立拉剪复合条件下抗剪连接界面的粘聚软化本构方程；采用增强有限元法，通过位移关联法则将结构物理区域与位移插值网格相独立，对抗剪连接界面开裂破坏等劣化过程的精细化模拟方法进行研究。基于位移协调和力的平衡关系，建立钢与混凝土间的非线性连接刚度分析计算公式，对抗剪连接区钢混相互作用的宏观模拟方法进行研究。基于Arlequin方法构架，通过能量分配函数和耦合算子，建立组合结构桥梁宏观特性与细观行为、整体性能与局部效应相关联的多尺度分析方法，实现对组合结构桥梁抗剪连接区复合受力条件下宏细观行为的分析，揭示其劣化机理，为组合桥梁的精细化设计和性能改善提供理论基础，以积极推动我国组合结构桥梁的健康发展。

Due to the complex mechanism and discontinuous deformation at the steel-concrete joints in composite bridges, the performance of the steel-concrete joints is difficult to determine. Whether the financial advantage of steel-concrete composite structures can be developed depends on the rationality of the shear joints setting. In this proposal, the cohesive zone model (CZM) will be applied to the failure simulation for shear connective interface of composite bridge. The cohesive softening constitutive equations of shear connective interface in the tensile-shear complex condition will be established. By use of Augmented finite element method(AFEM), the structural physical domain can be independent from displacement interpolation mesh through displacement relational principle, and the refined simulation method for degradation process such as cracking damage of shear connective interface will be studied. Based on the displacement compatibility and load equilibrium, the nonlinear equations to determine the stiffness of the connective steel-concrete joints will be developed, and the coupling effect of steel and concrete will be studied by the macroscopic simulation method. According to the Arlequin method, through the energy distribution function and coupling operator, the multi-scale dimension method based on the related macroscopic characteristics and microscopic behavior as well as the related general performance and local effect of bridge, will be developed, so that the analysis of micro and macro behavior of shear connective zone in composite bridge subjected to the complex loading conditions can be realized, and the degradation mechanism can be explored. It is expected that the proposal can provide the theoretical basis for delicate design and performance improvement of composite bridge, and urge a healthy development of composite bridge in China.