In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For th...In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For the same fracture density, the variations of the velocity and amplitude of the primary wave and shear wave parallel and perpendicular to the fracture were observed by altering the diameter （scale） of the penny-shaped fracture disk. The model test indicated that an increase of fracture scale increased the velocity and amplitude of the primary wave by about 2%. When the shear wave propagated parallel to the fracture, the velocity of the fast shear wave hardly changed, while the velocity of slow shear wave increased by 2.6% with increasing fracture scale. The results indicated that an increase of fracture scale would reduce the degree of anisotropy of the shear wave. The amplitudes of slow shear waves propagating parallel and perpendicular to fractures decreased with increasing fracture scale.展开更多
Employing density functional theory, we study the tensile and fracture processes of the phase interfaces in Mg–Li binary alloy. The simulation presents the strain–stress relationships, the ideal tensile strengths, a...Employing density functional theory, we study the tensile and fracture processes of the phase interfaces in Mg–Li binary alloy. The simulation presents the strain–stress relationships, the ideal tensile strengths, and the fracture processes of three phase interfaces. The results show that the α/α and α/β interfaces have larger tensile strength than that of β/β interface. The fractures of both α/α and β/β interfaces are ductile fractures, while the α/β fractures abruptly._Further analyses show that the fracture of the α/β occurs at the interface.展开更多
The fissures and rock bridges with different dips had different contributions to crack's initiation,propagation,convergence and penetration.In this paper,based on the rock fracture theory,the crack's propagati...The fissures and rock bridges with different dips had different contributions to crack's initiation,propagation,convergence and penetration.In this paper,based on the rock fracture theory,the crack's propagation and evolution process on rock specimen with double fissures under uniaxial compression was simulated.As a result,the crack propagation and evolution law of rocks with different fissure dips(α=0°,15°,30°,45°,60°,75°,90°;β=45°)and different rock bridge dips(β=0°,30°,45°,60°,90°;α=45°)was obtained by numerical tests.Meanwhile,the fissure and rock bridge dips influence on the macro mechanical properties of rock was analyzed.Besides,the paper investigated the influences of different fissure dips and different rock bridge dips on the bridge transfixion.The study is of great significance to reveal the impact of different dips on the mechanical mechanism of multiple-fissures rock under specific conditions,and it also has important theoretical significance for the research on multiple-fissure rock.展开更多
文摘In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For the same fracture density, the variations of the velocity and amplitude of the primary wave and shear wave parallel and perpendicular to the fracture were observed by altering the diameter （scale） of the penny-shaped fracture disk. The model test indicated that an increase of fracture scale increased the velocity and amplitude of the primary wave by about 2%. When the shear wave propagated parallel to the fracture, the velocity of the fast shear wave hardly changed, while the velocity of slow shear wave increased by 2.6% with increasing fracture scale. The results indicated that an increase of fracture scale would reduce the degree of anisotropy of the shear wave. The amplitudes of slow shear waves propagating parallel and perpendicular to fractures decreased with increasing fracture scale.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50874079,51002102,and 61205179)the Natural Science Foundation of Shanxi Province,China(Grant No.2009021026)
文摘Employing density functional theory, we study the tensile and fracture processes of the phase interfaces in Mg–Li binary alloy. The simulation presents the strain–stress relationships, the ideal tensile strengths, and the fracture processes of three phase interfaces. The results show that the α/α and α/β interfaces have larger tensile strength than that of β/β interface. The fractures of both α/α and β/β interfaces are ductile fractures, while the α/β fractures abruptly._Further analyses show that the fracture of the α/β occurs at the interface.
基金This work was financially supported by the Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(PLN1202)the Natural Science Foundation of China(51174170).
文摘The fissures and rock bridges with different dips had different contributions to crack's initiation,propagation,convergence and penetration.In this paper,based on the rock fracture theory,the crack's propagation and evolution process on rock specimen with double fissures under uniaxial compression was simulated.As a result,the crack propagation and evolution law of rocks with different fissure dips(α=0°,15°,30°,45°,60°,75°,90°;β=45°)and different rock bridge dips(β=0°,30°,45°,60°,90°;α=45°)was obtained by numerical tests.Meanwhile,the fissure and rock bridge dips influence on the macro mechanical properties of rock was analyzed.Besides,the paper investigated the influences of different fissure dips and different rock bridge dips on the bridge transfixion.The study is of great significance to reveal the impact of different dips on the mechanical mechanism of multiple-fissures rock under specific conditions,and it also has important theoretical significance for the research on multiple-fissure rock.
