Shale contains distributed directional bedding planes,which make the shale transverse isotropic.To model shale with consideration of the bedding planes,a cohesive finite element method(CFEM)is developed based on the r...Shale contains distributed directional bedding planes,which make the shale transverse isotropic.To model shale with consideration of the bedding planes,a cohesive finite element method(CFEM)is developed based on the randomized triangular mesh.The interface orientation generated from such mesh tends to be uniformly distributed with the element number increasing.To represent the bedding plane,the interfaces aligned with the bedding plane are assigned the cohesive law that characterizes the bedding plane while the other interfaces are assigned the cohesive law that characterizes the matrix.By this means,the anisotropy characteristics of the stiffness and the strength of shale are well represented.The simulation examples demonstrate that the bedding plane has a significant influence on the fracture trajectory,which is consistent with the observation in the experiment.It is suggested that this modeling method of shale is feasible.It provides an alternative approach to fracture simulation in shale.展开更多
It is pointed out that the evanescent light wave occurring at total reflection does not possess a transverse spin angular momentum as Bliokh, Bekshaev, and Nori claimed recently in (2014) Nature Communications, 5,3300...It is pointed out that the evanescent light wave occurring at total reflection does not possess a transverse spin angular momentum as Bliokh, Bekshaev, and Nori claimed recently in (2014) Nature Communications, 5,3300. This is not only because of the nonlocality of the photon spin but also because the evanescent wave is such a state whose angular momentum cannot be separated into spin and orbital parts.展开更多
基金supported by the National Natural Science Foundation of China(No.11772190)
文摘Shale contains distributed directional bedding planes,which make the shale transverse isotropic.To model shale with consideration of the bedding planes,a cohesive finite element method(CFEM)is developed based on the randomized triangular mesh.The interface orientation generated from such mesh tends to be uniformly distributed with the element number increasing.To represent the bedding plane,the interfaces aligned with the bedding plane are assigned the cohesive law that characterizes the bedding plane while the other interfaces are assigned the cohesive law that characterizes the matrix.By this means,the anisotropy characteristics of the stiffness and the strength of shale are well represented.The simulation examples demonstrate that the bedding plane has a significant influence on the fracture trajectory,which is consistent with the observation in the experiment.It is suggested that this modeling method of shale is feasible.It provides an alternative approach to fracture simulation in shale.
文摘It is pointed out that the evanescent light wave occurring at total reflection does not possess a transverse spin angular momentum as Bliokh, Bekshaev, and Nori claimed recently in (2014) Nature Communications, 5,3300. This is not only because of the nonlocality of the photon spin but also because the evanescent wave is such a state whose angular momentum cannot be separated into spin and orbital parts.
