本项目从混凝土材料内部缺陷问题着手，通过CT试验、数值试验、理论分析和对比验证等方法，对不同几何尺寸、不同细观结构的混凝土试件的细观损伤发展规律、宏观强度变化机理等问题开展重点研究。以混凝土CT试验、图像处理技术以及三维重建技术为手段，建立基于CT试验的混凝土细观结构缺陷的损伤演化方程，以及含有细观缺陷的混凝土材料数值试验模型，并将计算子程序嵌入分析当中，实现对细观缺陷分布、比例以及填充材料等相关参数的控制。从不同形式动荷载单独作用下，细观结构损伤演化分析入手，基于损伤力学、断裂力学理论，建立结构几何参数、细观缺陷相关参数与宏观强度参数之间的函数关系。并以此研究多种形式动荷载共同作用时，内部缺陷对细观损伤演化、宏观强度变化的作用机理，建立细观损伤发展与宏观强度变化之间的量化关系。以期为混凝土结构损伤破坏特性研究和有害裂纹防治提供理论基础与技术支撑。

The project focus on the internal defects in the concrete structure, and investigate the key point of the mechanism of macro-strength and development law of meso-damage in concrete struture with different geometric dimensioning and meso-structure, based on the CT test, numerical simulation, theoretical analysis and comparison. Taking the CT test, image processing techniques and dimensional reconstruction as the principal Methods, the damage evolution equation in the defective concrete model and defective concrete numerical model will be entered. The subroutine will be insertion in the analysis, therefore the distribution, proportion and material parameter can be controlled. From the analysis of meso-damage evolution in the concrete structure under the different dynamic loading, and based on the damage mechanics and Fracture mechanics, the functional relationship among the geometric dimensioning, relevant parameters of defect and macro-strength will be established. And then, the action mechanism of the defect on the meso-damage evolution and macro-strength changing under the various combination of different dynamic loading will be investigated. The quantitative relationship between the meso-damage evolution and macro-strength changing will be discussed. This project may provides a theoretical basis and technical support for controlling measure of damage in the concrete structure.