准脆性材料断裂过程区中的圆饼微裂纹损伤计算

准脆性工程材料及结构在外力作用下，不仅引起内部缺陷变化和微裂纹的出现及发展，且使得其结构承载能力降低或性能劣化．在其材料失效过程中常存在裂缝与断裂损伤过程区．为研究材料细观缺陷或微裂纹与宏观破坏的规律，通过细观力学方法，对于代表性体积单元RVE中的圆饼型微裂纹的尺寸与密度变化，探讨其宏观断裂过程区力学参量与损伤之间的量化关系．借助宏观断裂过程区的黏聚裂纹模型，将损伤单元RVE嵌入到宏观裂缝端部的断裂过程区中，对其进行联接细观损伤到宏观破坏的力学多尺度研究．文中也通过实验数据，对其理论计算结果进行了算例的讨论与分析．

Damage Calculation of Circular Cake Micro-Cracks in the Fracture Process Zone of Quasi-Brittle Materials

The deformation and damage of quasi-brittle engineering materials subjected to external forces can not only cause the development of defects or micro-cracks, but also lead to the bearing capacity reduction and the performance deterioration. During the fracture process, there usually exists a process zone of fracture and damage near an opening crack. In order to investigate the relation between the characteristics of mesoscopic defects or micro-cracks and the macroscopic failure processes, the dimension and density change of the circular cake micro-cracks in a representative volume element (RVE) are analyzed by means of mesomechanics method. By means of the crack cohesion model of macro fracture mechanics, the damage element RVE is embedded into the fracture process zone near a macro crack tip. This work consists of a multi-scale mechanical analysis from mesoscopic damage to macro fracture. Some examples are theoretically analyzed and discussed using the experimental test data.