钢管混凝土桁梁疲劳性能与损伤失效机理研究

Concrete filled steel truss girder has broad application prospect in bridge engineering due to its superior mechanical properties and easy for construction. In present, there is little research on the fatigue performance of this structure, the existing fatigue research mainly focuses on the fatigue performance of joint, while little research on the overall structure fatigue performance, the local damage failure mode and the global damage failure mode and the damage evolution law is to be studied. In order to improve the design and calculation theory of this structure, some further research should be carried out..This research focuses on the fatigue performance and the damage mechanism of concrete filled steel tubular truss girder under the fatigue load. Based on the study of fatigue damage failure, the mechanics model, the numerical fatigue simulation of overall structure and experiment, the relationship between local damage failure and the global damage failure is discussed. Also, the failure mode and damage analysis model of concrete filled steel tubular truss girder were established to study the fatigue damage mechanics characteristics, the damage evolution law and the failure mechanism. The research can give theoretical support for the fatigue design theory of the concrete filled steel tubular truss girder.

钢管混凝土桁梁具有优越的力学性能和施工上的方便，在桥梁工程中具有广阔的应用前景，但目前这种结构在疲劳方面的研究还比较少，现有的研究多集中在节点的疲劳性能方面，缺少整体疲劳性能的研究；疲劳荷载作用下钢管混凝土桁梁的局部和整体结构损伤失效模式和疲劳损伤累积发展规律方面的研究还有待于展开。.本项目以疲劳作用下钢管混凝土桁梁的疲劳性能和损伤失效机理为研究对象，通过对钢管混凝土桁架组合梁的疲劳损伤失效和力学模型研究、结构整体的数值模拟与试验研究，分析疲劳作用下的钢管混凝土桁梁的疲劳性能、探讨局部失效和整体失效之间的关系，建立钢管混凝土桁梁的失效模式和损伤分析模型，探索钢管混凝土桁梁的疲劳损伤力学特性，损伤演变规律和失效机理，项目的研究可为钢管混凝土桁梁疲劳设计理论的发展提供理论基础。