Shear fractures in anisotropic ductile materials: an experimental approach
Analogue models have been used to investigate the influence of planar mechanical anisotropy on the orientation of shear fractures in an elastoviscous-brittle material. Multilayered models consisting of a mixture of plasticine, vaseline and preferentially-oriented paper flakes have been coaxially def...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/201760 |
| Acceso en línea: | https://hdl.handle.net/2445/201760 |
| Access Level: | acceso abierto |
| Palabra clave: | Anisotropia Geologia estructural Anisotropy Structural geology |
| Sumario: | Analogue models have been used to investigate the influence of planar mechanical anisotropy on the orientation of shear fractures in an elastoviscous-brittle material. Multilayered models consisting of a mixture of plasticine, vaseline and preferentially-oriented paper flakes have been coaxially deformed for this purpose. The evolution of the orientation, length and connectivity of fracture sets has been systematically analysed with progressive coaxial deformation. The experimental results show that the orientation of fractures with respect to the deformation axes depends on the orientation of transverse anisotropy. Two symmetrical sets of shear fractures are formed in models with layering parallel to the extension axis X, while the fracture network is asymmetrical with respect to the deformation axes for cases with oblique anisotropy. The average dihedral angles between fracture sets are higher than 100°, with the obtuse bisector between the two sets oriented perpendicular to layers. The stress fields calculated from fracture data differ from the boundary conditions applied by the deformation apparatus. This misorientation is related to the degree of anisotropy. In models with high oblique anisotropy both fracture arrays rotate in a dextral sense together with layers towards the X-axis, indicating that the presence of a strong anisotropy controls their evolution with progressive deformation. |
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