New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction
Existing models of brittle shear failure are unable to account for three-dimensional deformation involving the development of polymodal sets of fractures. Motivated by field observations of contemporaneous arrays of quadrimodal faults and deformation bands, we use an idealised micromechanical model...
| Main Authors: | , , |
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| Format: | Journal Article |
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Elsevier Science BV
2006
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| Online Access: | http://hdl.handle.net/20.500.11937/37265 |
| _version_ | 1848754999111188480 |
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| author | Healy, David Jones, R. Holdsworth, R. |
| author_facet | Healy, David Jones, R. Holdsworth, R. |
| author_sort | Healy, David |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Existing models of brittle shear failure are unable to account for three-dimensional deformation involving the development of polymodal sets of fractures. Motivated by field observations of contemporaneous arrays of quadrimodal faults and deformation bands, we use an idealised micromechanical model to explain how brittle shear fractures can form oblique to all three remote principal stresses. We model tensile microcracks as finite ellipsoidal voids, subjected to small opening strains, in a linear isotropic elastic matrix. The geometry of the tensile stress lobes around the ends of an isolated microcrack promotes the en echelon interaction of neighbouring cracks with respect to the prescribed crack orientation. Coalescence of these interacting crack arrays into a through-going composite fracture surface leads to a brittle shear failure plane oriented obliquely to all three coordinate axes and all three remote principal stresses. Experimental evidence supports the idea that composite shear fractures can propagate in-plane through the coalescence of many constituent tensile microcracks. Our new model, based on the 3-D geometry of the elastic stress field around a mode I crack, can explain the oblique orientations of polymodal faults formed in a triaxially compressive stress field. |
| first_indexed | 2025-11-14T08:49:19Z |
| format | Journal Article |
| id | curtin-20.500.11937-37265 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:49:19Z |
| publishDate | 2006 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-372652017-09-13T13:38:55Z New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction Healy, David Jones, R. Holdsworth, R. Interaction Fracture Microcrack Quadrimodal Polymodal Fault Existing models of brittle shear failure are unable to account for three-dimensional deformation involving the development of polymodal sets of fractures. Motivated by field observations of contemporaneous arrays of quadrimodal faults and deformation bands, we use an idealised micromechanical model to explain how brittle shear fractures can form oblique to all three remote principal stresses. We model tensile microcracks as finite ellipsoidal voids, subjected to small opening strains, in a linear isotropic elastic matrix. The geometry of the tensile stress lobes around the ends of an isolated microcrack promotes the en echelon interaction of neighbouring cracks with respect to the prescribed crack orientation. Coalescence of these interacting crack arrays into a through-going composite fracture surface leads to a brittle shear failure plane oriented obliquely to all three coordinate axes and all three remote principal stresses. Experimental evidence supports the idea that composite shear fractures can propagate in-plane through the coalescence of many constituent tensile microcracks. Our new model, based on the 3-D geometry of the elastic stress field around a mode I crack, can explain the oblique orientations of polymodal faults formed in a triaxially compressive stress field. 2006 Journal Article http://hdl.handle.net/20.500.11937/37265 10.1016/j.epsl.2006.06.041 Elsevier Science BV restricted |
| spellingShingle | Interaction Fracture Microcrack Quadrimodal Polymodal Fault Healy, David Jones, R. Holdsworth, R. New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title | New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title_full | New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title_fullStr | New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title_full_unstemmed | New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title_short | New insights into the development of brittle shear fractures from a 3-D numerical model of microcrack interaction |
| title_sort | new insights into the development of brittle shear fractures from a 3-d numerical model of microcrack interaction |
| topic | Interaction Fracture Microcrack Quadrimodal Polymodal Fault |
| url | http://hdl.handle.net/20.500.11937/37265 |