摘要
Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force- displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens made of sandstone-like modeling material contained three pre-existing intermittent cracks with different geometrical distributions. The experimental results indicate that the fatigue deformation limit corresponding to the maximal cyclic load is equal to that of post-peak locus of static complete force?displacement curve; the fatigue deformation process can be divided into three stages: initial deformation, constant deformation rate and accelerative deformation; the time of fracture initiation, propagation and coalescence corresponds to the change of irreversible deformation.
Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force- displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens made of sandstone-like modeling material contained three pre-existing intermittent cracks with different geometrical distributions. The experimental results indicate that the fatigue deformation limit corresponding to the maximal cyclic load is equal to that of post-peak locus of static complete force-displacement curve; the fatigue deformation process can be divided into three stages: initial deformation, constant deformation rate and accelerative deformation; the time of fracture initiation, propagation and coalescence corresponds to the change of irreversible deformation.
基金
Projects(50479023, 50708034) supported by the National Natural Science Foundation of China
Project(20070532069) supported by Specialized Research Fund for the Doctoral Program of Higher Education
Project (20060400263) supported by China Postdoctoral Science Foundation
Project(2007RS4031) supported by Provincial Science and Technology Plan of Hunan
关键词
岩石力学
疲劳特性
周期载荷
裂纹产生
疲劳损坏
rock mechanics
fatigue properties
cyclic loading
fracture evolution
fatigue damage