采用钢悬臂拓宽混凝土箱梁的新型组合结构破坏机理及优化设计研究

项目名称： 采用钢悬臂拓宽混凝土箱梁的新型组合结构破坏机理及优化设计研究

项目编号： No.51308090

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 王骞

作者单位： 大连理工大学

项目金额： 25万元

中文摘要： 采用钢悬臂拓宽后的箱梁结构为一种新型的钢-混凝土组合结构，该结构为城市箱梁桥的拓宽提供了一种无需增设桥墩的有效模式。项目采用理论分析、模型试验、数值模拟相结合的方法，探索组合结构梯度构件的破坏机理；通过开展组合结构梯度构件破坏试验，获得结构失效的控制参数，构建能够考虑材料非线性、粘结滑移非线性、接触非线性等诸多因素的有限元分析模型，探讨不同结构参数对组合结构梯度构件的受力、变形以及破坏过程的影响规律，揭示其破坏机理。同时开展组合结构梯度构件的优化设计研究，提出基于梯度构件受力性能的优化设计模型及基于损伤容限的优化设计模型，研究相应的求解策略，通过优化设计确定梯度构件的合理结构参数，并通过试验验证优化设计的有效性。研究结果可以为复杂组合结构的破坏机理分析及设计提供有效思路和理论依据，并为箱梁桥拓宽技术的进步提供理论支持。

中文关键词： 混凝土箱梁；钢悬臂拓宽法；新型组合结构；破坏机理；优化设计

英文摘要： The structure of box girder widened by steel cantilevers is a new kind of steel-concrete composite structure which supplies an effective widening pattern for urban bridge without additional piers. By means of model test, numerical stimulations and theoretical analysis, the failure mechanism of the composite structure graded component is investigated. The failure control parameters of the graded component are gotten by the destruction tests. Based on the test results, the finite elements mathematical model considering the material nonlinearity, bond-slip effect and the contact nonlinearity is established. The influence rules of the structural parameters on the stress, deformation and failure process of graded components are studied and the failure mechanism of the composite structure is exposed.During the study of graded component optimal design, the optimal models based respectively on the mechanical characteristics and damage tolerance of the graded component are proposed and the solving strategy are presented too. The rational structure parameters of the graded component are gotten by optimal analysis and the effectiveness of the optimal design is validated by tests. The study results not only provide the effective way for the failure mechanisms analysis and design of complex composite structures but also prom

英文关键词： Concrete box girder；Steel cantilever widening method；New composite structure；Failure mechanism；Optimal Design