Linear Elastic Fracture Mechanics Characterization of an Anisotropic Shale.
Linear Elastic Fracture Mechanics Characterization of an Anisotropic Shale.
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各向异性页岩的线弹性断裂力学表征
DOI：
10.1038/s41598-018-26846-y
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发表时间：
2018-05-31
影响因子：
4.6
通讯作者：
Gao C
中科院分区：
文献类型：
--
作者：
Luo Y;Xie HP;Ren L;Zhang R;Li CB;Gao C
天然页岩地层中层理面的存在使得裂缝表征异常复杂。为进一步利用线弹性断裂力学方法了解页岩各向异性裂缝扩展行为，对渝东南龙马溪页岩进行了4组不同层理面倾角的三点弯曲试验。用扫描电镜观察了断口的扩展路径。结果表明：当层理平面倾角（即加载方向与层理平面法线方向夹角）较大时，裂缝沿层理平面产生；层理平面倾角越小，裂纹越深入基体，断裂韧性越高。试验页岩存在脆性裂缝，裂缝强度与层理面倾角密切相关。同时，对裂纹尖端周围的应力场进行了理论分析。结果表明，各向异性页岩裂纹尖端应力场不仅由应力强度因子决定，还与弹性常数和层理面倾角有关。此外，通过区分页岩层理与基质强度的差异，建立了裂缝是否沿层理平面延伸的判据。
The existence of bedding planes in natural shale formations makes the fracture characterization remarkably complicated. To achieve a further understanding of the anisotropic crack extension behaviors of shale using a linear elastic fracture mechanics approach, four groups of three-point bending tests on Longmaxi shale from southeast Chongqing were conducted in this study with different bedding plane inclination angles. The fracture propagation paths were observed using a scanning electron microscope. The results indicated that cracks initiated along the bedding plane when the bedding plane inclination angle (i.e., the angle between the loading direction and the normal direction of the bedding plane) was relatively large; in contrast, cracks penetrated into the matrix and induced higher fracture toughness in cases with lower bedding plane inclination angle. Brittle fractures occurred in the tested shale, and the fracture strength was strongly dependent on the bedding plane inclination angle. Meanwhile, the stress field around the crack tip was analyzed theoretically. The results indicated that the crack tip stress field of anisotropic shale is not only determined by the stress intensity factor but also related to the elastic constants and bedding plane inclination angle. Furthermore, a criterion for determining whether a crack extends along the bedding plane was developed by distinguishing the differences in the strengths of the shale bedding and the matrix.
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影响因子：
3.9
作者：
Chandler, Michael R.;Meredith, Philip G.;Crawford, Brian R.
通讯作者：
Crawford, Brian R.
DOI：
10.1016/j.ijrmms.2016.07.005
发表时间：
2016-10-01
影响因子：
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作者：
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通讯作者：
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DOI：
10.1016/0020-7683(92)90138-j
发表时间：
1992-01-01
影响因子：
3.6
作者：
BAO, G;HO, S;FAN, B
通讯作者：
FAN, B
DOI：
10.1016/j.ijengsci.2012.06.005
发表时间：
2012-12-01
影响因子：
6.6
作者：
Mishuris, Gennady;Wrobel, Michal;Linkov, Alexander
通讯作者：
Linkov, Alexander
DOI：
10.1016/s0148-9062(96)00053-8
发表时间：
1997-01-01
影响因子：
7.2
作者：
Niandou, H;Shao, JF;Fourmaintraux, D
通讯作者：
Fourmaintraux, D