考虑界面影响的钢纤维混凝土细观力学等效性能研究

Micromechanics Equivalent Performance Study of Steel Fiber Reinforced Concrete with Interface Layers

钢纤维与混凝土基体之间的界面对钢纤维混凝土(SFRC)发挥其增强、增韧作用具有重大影响,故为了考证其微观结构特征,探讨SFRC微观结构与其宏观性能之间的关系.考虑了在无限各向同性平面内分布的圆形钢纤维,采用超奇异积分方程和复变函数等方法建立纤维、界面和基体上的应力、应变和位移等的分析模型.采用Galerkin积分方法和Gauss-Seidel迭代方法获得在平面应变条件下具有不同体积率和界面层厚度的钢纤维混凝土等效参数,讨论了钢纤维体积率以及界面层厚度对材料等效参数的影响,并通过与相同条件下宏观试验得出的结果相比较,结果表明,本模型能够较为准确地分析钢纤维混凝土的宏观弹性参数.

The interfaces between fiber and matrix have significant effect on the toughness and strength of steel fiber reinforced concrete （SFRC）. Therefore, a model is built, that is to investigate the character of its micro structure of SFRC and the relationship between its microstructure and its macroscopic properties, by using hyper singular integral equations and complex function. This model is about the unknown stress, strain and displace ment on the boundary of fiber, matrix, and interface with considering that fibers randomly distribute in an infi nite and isotropic plane. The equivalent elastic modulus of SFRC under plane strain conditions is obtained by u sing the Galerkin integral method and GaussSeidel iterative algorithm method. The influence of the the thick ness of interface and the volume fraction of the steel fiber on the elastic modulus is investigated. The numerical results show that both thickness of interface and volume fraction of steel fiber have significant effects on the elas tic modulus of the steel fiber reinforced concrete. Then the accuracy, efficiency, and versatility of the model are demonstrated by comparing the numerical results with the results from the test with the same conditions.